Question International ROM for XIAOXIN PAD PRO 2021 unlikely?

[mardon85]

As I tried to explain in #138 the thing you're referring too and the picture you repasted in #104, looks a lot like the ZUI transparency feature where things underneath will shine through and almost give that old IPS-blooming-effect, but on P11pro2021 it looks (as far as I can tell) like it's with intent, and a feature of the Android skin Lenovo are using.

Are you sure it ain't that "ZUI transparency feature" you mistakenly take as "grey problems" as you expressed above to the picture #104 that was posted that certainly looks a lot like the pictures I showed of the OS transparency feature? in post #138
also why I hope'd you would demonstrate it.? (as you mentioned a few months back you would in #132)
As then I could try to replicate it and see if you got a bad batch, or it's a revision issue, or it's common?

- as it ain't magic and if there is problems with grey toning. you would see it with finer and finer grey slide-lines or in different grey or black scales like the examples above, but in the few tests I have made, and where such things usually would be elevated, - I don't see anything, quite the contrary, I'm very impressed with the OLED display Lenovo er using and it blew my mind the prices this tablet is being sold at, like 350 USD, but it also looks like it originally was sold at a way higher CN price back in the day

- and here in the west, the older little brother P11pro2020 (J-706) just entry version' is still from +655 USD on Lenovo dk (Denmark) (4299 DKK) so the J-716 would likely be +750 to 850 USD if Lenovo had released that model in the west.(no wonder that people turn to foreign markets, with such price mockup.

Tab P11 Pro | Premium 11,5" tablet med 2K-skærm

Få flere oplysninger om Lenovo Tab P11 Pro, en førsteklasses 11,5" tablet med en 2K OLED-skærm, octa-core-processorkraft og understøttelse af digital pen.

www.lenovo.com

I also have Samsung AMOLED displays, so I can compare one to the other and my girl's parents have an S7+.
The E4 is an older AMOLED blue-stripe panel and certainly also has its weaknesses and almost no change from E3, likely also why we are seeing a new generation E5 in the second half of 2021 and now in the start of 2022 and on Tab S8+ and Ultra and numerous third-party mobiles.
Personally, I prefer the Xiaoxin ability to show red. often a problematic color to get deep and vibrant as it is choking into orange..

I'm also impressed by the Xiaoxin P11pro2021 DC dimmed panel and its brightness ability.
I'm seeing some of the highest brightness values I have seen on any tablet on the Xiaoxinp11pro2021 and way higher than fx P11pro2020.

with the brightness sliders it tops out a tad over +600nits.. like 630nits, but if you activate the extreme brightness effect and trigger the lightsensor. it goes up to just under 900nits. (that ain't too shabby in full white)
- and it does inform you on the screen when it goes into this extreme brightness mode and also when it goes out of it. (the max seems to be around 900nits and I don't know how long it can sustain it)
Example..

https://imgur.com/ICIOiOn

plain sliders. (a tad over 600nits)

https://imgur.com/JttHqrI

As a person that is fascinated by display technologies, I love the fact that it ain't a very common OLED panel in the P11pro2021, as we have seen the Samsung E4 AMOLED panel in so many products and also in sub200 budget tablet brands, like Alldocube, and Chuvi, ... the Samsung E4 panel is very common and I reckon most people have an item with that AMOLED E4 tech in house and why I find it interesting to get access to other manufactures OLED technologies and being able to compare variables and pro & cons.

The biggest con on these Lenovo / Xiaoxin P11pro2021 / P12 is the OS.. kinda half-baked from a western viewpoint, hence the lack of western release - but some things the ZUI-OS is actually doing better than my Samsungs DeX Tablets.
fx video-out looks to be in 4K.. my LG 4K OLED TV (2017) does list it as a 4K signal but in like a 4:3 ratio.. where I otherwise the max are 1440p on Samsung.

Was also pleasantly surprised to see the wireless-display interaction with LG OLED TVs and the wireless-display quality and the LG remote control-pointer function as an android mouse..
makes it a blast to stream Magellan & Wondrium and the other science stream channels up on the big screen, without cables.

For someone that clearly enjoys oled are you really telling me you can't see the grain effects on red colours?

It's 100% not the os transparency effect. Dim the screen and look at this web page and report back.

The issue with films is largely fixed by setting the screen to 60hz. 95% of the content I watch is in HDR and their is a bug that elevates the black after a few seconds on certain players. My go to is "justplayer". Again other people are reporting the same.
Perhaps they fixed some off the issues I'm seeing at a hardware level between yours and mine.
This isn't opinion or preferring once device over the other due to which I own. It is a genuine issue on mine and other people's devices.

Also who cares if it can do 900nits if you activate the light sensor, just like the red test pattern it's not something you see in day to day usage. Know one sits consuming content with a torch pointing at the sensor. They both output 600nits which is totally fine for indoor use.

 

[Temjinck]

From reading the thread, can I presume that it is much more desirable to buy the tablet straight from China (i.e. taobao) with native Chinese ROM instead of an unofficial global from?

I really needed the tablet to run google play services and google play store flawlessly, including games that use play game services for profile backup. Also good to have is OTA updates and streaming apps.

Otherwise, what other limitations am I looking at with the Chinese ROM? Someone talked about regional locks here, what do you mean by that?

I've used a Huawei Honor 5 with Chinese ROM and google play service/google play store simply do not work consistently. Just don't want to deal with this problem again.

 

[Wualk]

I can also confirm what @mardon85 has noticed and described. Especially in a very dark environment (e.g. in your bedroom in the evening) when watching Netflix there is a noticeable "flickering" of blacks/greys in the screen. This happens mostly when watching a dark movie scene and when you have turned down the brightness.

I must also thank mardon85 because your solution worked. Previously I had disabled auto brightness etc., but this did not help me. Lowering the refresh rate to 60 did solve it for me (and just for the record, I have also changed the image settings from vivid to natural).

And no, it has nothing to do with the transparency overlay. That works as expected. Kinda.

 

[EvilGuy88]

According to a YouTuber, Lenovo pad pro 12 has the same screen issue as pro 11.

 

[mardon85]

According to a YouTuber, Lenovo pad pro 12 has the same screen issue as pro 11.

Can you share a link? I have zero issues with the screen it's awesome!

 

[EvilGuy88]

Can you share a link? I have zero issues with the screen it's awesome!

Skip to 5:30

 

[mardon85]

Skip to 5:30

Not noticed it personally and I've come from the 2021 P11 Pro so knew what to look for. It there is an issue it's certainly not the same one and not something I've seen. I'll check again tonight though.
Was possibly a software issue in the first un patched ROM which is what he's running in the review.

 

[Josephand28]

hello I need the global firmware of zui 12.5 for lenovo TBJ716F Someone who knows a repository where I can download it, or someone who has a copy of the firmware thanks

 

[Maximozavr]

здравствуйте мне нужна глобальная прошивка zui 12.5 для lenovo TBJ716F кто знает репозиторий где можно скачать или у кого есть копия прошивки спасибо

I only found this one 12.6.211 : https://mirrors.lolinet.com/firmware/lenovo/Tab_P11_Pro_2021/TB-J716F

 

[0Newbie0]

I'm really happy for you that you dont see it. I would suggest don't go searching to see something if it is not immediately obvioius.

However I did a lot of low light reading with my 2021 P11 Pro and it often manifested itself when the brightness was turned down low. Infact this very website was quite good at displaying the issue. The dirty screen would also be obvous on dimmer viewing of dark films.
If you dont use your tablet in this senario it is a non issue.

Having spent more time with the P12 pro I can confrim the screen is night and day better. I would find the grainy fringing arould colours especially red based ones very distracting. This does not happen in the slightest on the P12 e4 AMOLED. Yes a full screen red test patern may lean more toward the orange end of spectrum compared to the P11 but I don't watch test paterns, I watch movies and TV.

Did you get your P12 pro with global or Chinese ROM?

 

[DaneLaw]

For someone that clearly enjoys oled are you really telling me you can't see the grain effects on red colours?

It's 100% not the os transparency effect. Dim the screen and look at this web page and report back.

The issue with films is largely fixed by setting the screen to 60hz. 95% of the content I watch is in HDR and their is a bug that elevates the black after a few seconds on certain players. My go to is "justplayer". Again other people are reporting the same.
Perhaps they fixed some off the issues I'm seeing at a hardware level between yours and mine.
This isn't opinion or preferring once device over the other due to which I own. It is a genuine issue on mine and other people's devices.

Also who cares if it can do 900nits if you activate the light sensor, just like the red test pattern it's not something you see in day to day usage. Know one sits consuming content with a torch pointing at the sensor. They both output 600nits which is totally fine for indoor use.

I reckon it went over your head.. the use of 900 nits brightness on Lenovo P11pro2021 comes in handy with certain use-cases in bright sunlight - as you hopefully can conclude on your own.
instead of making a braindead example, like "who would be watching movies with a flashlight to trigger maximum brightness"
c'mon bud.. a tablet can be used for other things than just watching movies.
The 900nits maximum brightness feature, is intended for bright sunlight, if your using the tablet fx outside, or in a car, - or as I often do, as a 1600p OLED screen for DJI drones, - the native sustained brightness is at 625nits..
People have different use-cases for their tablets, not only watching movies, and it's a nice feature to have on mobile items like tablets, and mobiles that the item can peak brightness in certain well-lit environments..

I haven't noticed any of these things you referring to, but I'm also running native CN OS and haven't put any third-party ROMs on it, or flashed it back and forward with different ROMs, and many models are being sold of this unit - are being sold with third-party multilingual ROMs. (not sure if your unit is one of those)
But I was trying to help, and I kept backing it up with videos. and pictures and examples... simply to demonstrate where it excels and where it doesn't - but it needs to be repeatable.. just claiming I get some issues in something I'm watching, is a relative as it comes and not easy for others to check or validate, as it can be down to numerous things., and I don't recall I have seen any examples from you..

That you have grainy "reds"....don't take for granted that it's the same for all other people with a P11pro2021 - with your statement. - // "you like OLEDs and you can't even see the grainy reds".
If you take a screentest-app.. and chose red and even dial brightness back and forward..does it look solid, if it does, then it ain't fundamental.
You could clearly see how coherent the RED looked in a side-by-side with 1600p AMOLED panel.

So far you haven't delivered even one example to repeat these things as I recall - so it doesn't make much sense to debate it further if there are no tangible examples.
you DID state that you would show an example.. didn't you??. (have I missed it, then my bad??)

and you even stated it was a "pentile display", which I explained to you it wasn't and Pentile displays are a Samsung trademark, and this wasn't a pentile display as per se' as it had an equal amount of RGB subpixels..

The biggest drawback with these Lenovo tablets is the OS.. which seems kind of half-baked IMO.. the hardware is top nudge' fronting flagship-level.. not least for a sub 350 USD device delivering 725k in Antutu and IMO the ideal framerate for different use-cases, like video or gaming with 90hz for an SD870 Soc with a DC dimmed RGB OLED panel and a 1TB SD storage slot.

Certain media players can cause problems with HDR metadata, not least when this device also supports dynamic HDR (frame by frame) and not just static HDR.. again I don't know if flickering can be down to that. or the mediaplayer your using.

- at the end of the day, it's Lenovo.. it's not like their firmware & software is the gold standard.. often quite half-baked... even products intended for the western market can be a hard sell. -. it's the low price that makes this product stand out.

-----

Just check the colorcharts for the differentOLED-tablets, and as I showed in my colorslide-video the color reproduction that is being delivered with this Lenovo/Xiaoxin 1600p RGB OLED in P11pro2021 is better than what I'm seeing on AMOLED. E3, E4, E5.
Sadly Notebookcheck did not check the SD870 variant but they did check another Lenovo unit. (P11proSD730) that seems to have the same 1600p RGB OLED display (just run at lower framerate and lower brightness) and they also saw better colors on that RGB OLED than on Lenovo P12's E4 AMOLED.
Calman color-checker.
_Lower is better_
AMOLED E4 blue S-stripe panel in Lenovo P12pro.
P12pro dE2000 3.43
P12pro dE2000 max. 7.25 (wow)

P11pro dE2000 1.8
P11pro dE2000max 4.2

The P12pro color check scores are not good, they are around the 1350p IPS in Yoga Pro13, but that is IPS.
even Samsung own flagship Tab S7plus own AMOLED E4 panel. are delivering worse colorcheck-scores (dE2000 2.4) than the 1600p RGB OLED panel that was in the P11pro (dE2000 1.8) a dE2000 at 1.8 is flagship ApplePro mini-LED level..

And it falls in line with what I saw when comparing the colors of the RGB OLED in P11pro2021 vs AMOLED ..
the p11PRO2021 RED subpixels does seem more coherent then on AMOLED. https://tinyurl.com/2p9d63yw
Im quite impressed by the 1600p RGB OLED panel that are in P11pro2021 and its even beating Samsung tabS7+ and is also ahead of Apples current tablet flagship Ipad Pro 12.9 MiniLED on color check scores, and when you then have in mind - it's a sub 350 tablet.
- not to shabby 90HZ DC dimmed 625nits 1600p RGB OLED panel Lenovo is using in the P11pro2021.

_ added Calman color check-scores for new gen E5 AMOLED (Notebookcheck)
14.6" (E5 AMOLED)
Tab S8ultra dE2000 2.7
Tab S8ultra dE2000max 5.3

12.4" (E5 AMOLED)
Tab S8plus dE2000 2.2
Tab S8plus dE2000max 4.9

 

[mardon85]

I reckon it went over your head.. the use of 900 nits brightness on Lenovo P11pro2021 comes in handy with certain use-cases in bright sunlight - as you hopefully can conclude on your own.
instead of making a braindead example, like "who would be watching movies with a flashlight to trigger maximum brightness"
c'mon bud.. a tablet can be used for other things than just watching movies.
The 900nits maximum brightness feature, is intended for bright sunlight, if your using the tablet fx outside, or in a car, - or as I often do, as a 1600p OLED screen for DJI drones, - the native sustained brightness is at 625nits..
People have different use-cases for their tablets, not only watching movies, and it's a nice feature to have on mobile items like tablets, and mobiles that the item can peak brightness in certain well-lit environments..

I haven't noticed any of these things you referring to, but I'm also running native CN OS and haven't put any third-party ROMs on it, or flashed it back and forward with different ROMs, and many models are being sold of this unit - are being sold with third-party multilingual ROMs. (not sure if your unit is one of those)
But I was trying to help, and I kept backing it up with videos. and pictures and examples... simply to demonstrate where it excels and where it doesn't - but it needs to be repeatable.. just claiming I get some issues in something I'm watching, is a relative as it comes and not easy for others to check or validate, as it can be down to numerous things., and I don't recall I have seen any examples from you..

That you have grainy "reds"....don't take for granted that it's the same for all other people with a P11pro2021 - with your statement. - // "you like OLEDs and you can't even see the grainy reds".
If you take a screentest-app.. and chose red and even dial brightness back and forward..does it look solid, if it does, then it ain't fundamental.
You could clearly see how coherent the RED looked in a side-by-side with 1600p AMOLED panel.

So far you haven't delivered even one example to repeat these things as I recall - so it doesn't make much sense to debate it further if there are no tangible examples.
you DID state that you would show an example.. didn't you??. (have I missed it, then my bad??)

and you even stated it was a "pentile display", which I explained to you it wasn't and Pentile displays are a Samsung trademark, and this wasn't a pentile display as per se' as it had an equal amount of RGB subpixels..

The biggest drawback with these Lenovo tablets is the OS.. which seems kind of half-baked IMO.. the hardware is top nudge' fronting flagship-level.. not least for a sub 350 USD device delivering 725k in Antutu and IMO the ideal framerate for different use-cases, like video or gaming with 90hz for an SD870 Soc with a DC dimmed RGB OLED panel and a 1TB SD storage slot.

Certain media players can cause problems with HDR metadata, not least when this device also supports dynamic HDR (frame by frame) and not just static HDR.. again I don't know if flickering can be down to that. or the mediaplayer your using.

- at the end of the day, it's Lenovo.. it's not like their firmware & software is the gold standard.. often quite half-baked... even products intended for the western market can be a hard sell. -. it's the low price that makes this product stand out.

as I showed in this video the color reproduction that is being delivered with the RGB OLED in Lenovo P11pro2021 is better than what Im seeing on AMOLED.
Notebookcheck review.
Sadly Notebookcheck did not check the SD870 variant but they did check another Lenovo unit. (SD730) that seems to have the same RGB OLED display (just run at lower framerate and lower brightness) and they also saw better colors on that RGB OLED than on Lenovo P12's E4 AMOLED.
Calman color-checker.
lower is better._
AMOLED E4 blue S-stripe panel in Lenovo P12pro.
P12pro dE2000 3.43
P12pro dE2000 max. 7.25 (wow)

P11pro dE2000 1.8
P11pro dE2000max 4.2

The P12pro color check scores are not good, on Lenovo P12pro they are around the IPS in Yoga Pro, but that is IPS.
even Samsung own flagship Tab S7plus own AMOLED E4 panel. are delivering worse colorcheck-scores (dE2000 2.4) than the 1600p RGB OLED panel that was in the P11pro (dE2000 1.8) a dE2000 at 1.8 is ApplePro mini-LED level..

and it falls in line with what I saw when comparing the colors of the RGB OLED in P11pro2021 vs AMOLED ..
the Lenovo RED subpixels does seem more coherent than on AMOLED. https://tinyurl.com/2p9d63yw
Im quite impressed by the RGB OLED panel that are in P11pro2021 and its even beating Samsung tabS7+ and is also ahead of Apples current tablet flagship the Ipad Pro 12.9 MiniLED on color check scores, and when you then have in mind it's a sub 350 tablet..
not to shabby 90HZ DC dimmed 625nits 1600p RGB OLED panel Lenovo is using in the P11pro2021.

added Calman color check-scores for new gen E5 AMOLED (Notebookcheck)
Tab S8ultra dE2000 2.7
Tab S8ultra dE2000max 5.3

Tab S8plus dE2000 2.2
Tab S8plus dE2000max 4.9

I'm glad you're enjoying the screen so much you felt the need to return after all of this time to continue a discussion I have no real interest in continuing.

To my eyes and use case (watching films in a dim room) the P12 pro's screen is far superior and doesn't present the grain affect other users have also spotted.

Fair enough regarding the nits comment I did overlook it as it not my use case.

I should also add HDR and HDR10 are broken on both tablets where the black levle is raised significantly. Dolby Vison is fine thankfully but if content is not available in DV I will chose SDR over HDR. Lenovo is a junk company when it comes to software. If only Samsung supported DV I'd have ditched the tablet some time ago.
Nice/ok hardware poor software.

Enjoy your tablet.

 

[DaneLaw]

To my eyes and use case (watching films in a dim room) the P12 pro's screen is far superior and doesn't present the grain affect other users have also spotted.

Yep' confirmation bias is a powerful factor and tried to decipher if you had issues but since you never delivered the examples, you stated you would.. it makes it difficult to relate' - and oh yeah.. certainly have spent enough time on this with you, trying to help you find the cause.

if you get the time.. you can check the color accuracy test on the P12Pro on Notebookcheck and see' that they are nothing to write home about on Lenovo's E4 in their P12pro..
Actually, some of the worst amongst all OLED-tablets when it comes to color check-accuracy values, while the P11pro is topping the dE2000 charts, and that's quite remarkable for such a cheap tablet-. and what I also noticed when comparing AMOLED with P11pro2021 and what I tried to example on video with "side-by-side"..
- and why it puzzled me that you kept saying how good the screen on your new P12pro in regards to P11pro2021, and it was literally "night and day" - when the facts on neutral third-party sites like Notebookcheck, and my own impression were the exact opposite.

I wondered about the cause and if it could be down to a non-native multilingual ROM / flashing, or a faulty unit - and if there was any chance that I could copy your problems, but clearly impossible' when its so relative and nothing tangible and nothing specific is mentioned that I can replicate for you..
but some things do look good in some eyes and vice versa in others, the most important thing - is that you're happy with your tablet, and yeah "Lenovo" leaves a lot to be desired when it comes to firm/software..but that's the norm and why the "deal" had to be so strong on inner hardware-values - before it makes sense to jump into bed with them.
Thx, you too...
cheers.

 

[mardon85]

Yep' confirmation bias is a powerful factor and tried to decipher if you had issues but since you never delivered the examples, you stated you would.. it makes it difficult to relate' - and oh yeah.. certainly have spent enough time on this with you, trying to help you find the cause.
if you get the time.. you can check the color accuracy test on the P12Pro on Notebookcheck and see' that they are nothing to write home about on Lenovo's E4 in the P12pro.. actually, some of the worst amongst all OLED tablets when it comes to color check-values, while the P11pro is topping the charts, and that's quite remarkable for such a cheap tablet-. and what I also noticed when comparing AMOLED with P11pro2021 and what I tried to example on video with "side-by-side".. and why it puzzled me that you kept saying how good the screen on your new P12pro in regards to P11pro2021,a nd it was "night and day" - when the facts on neutral third-party sites like Notebookcheck, and my own impression was the exact opposite..
I wondered about the cause and if it would be down to a non-native multilingual ROM or or a previous flashing, or a faulty unit - and if there was any chance that I could copy your problems, but clearly impossible when its so relative and nothing tangible and nothing specific is mentioned that I can replicate for you..
but some things do look good in some eyes and vice versa in others, the most important thing - is that you're happy with your tablet, and yeah "Lenovo" leaves a lot to be desired when it comes to firm/software..but that's the norm and why the "deal" had to be so strong on inner hardware-values - before it makes sense to jump into bed with them.
Thx, you two...
cheers.

I'm not talking about colour accuracy though. People's preference for colour is one thing accuracy is another. Why do you think Samsung over saturate their TV's. The general population prefer colour pop. In not doing anything professional on the tablet so its really a none issue.
I appreciate you may be trying to help but I don't need any help. I didn't have an isolated software issue that needed diagnosing and you'll see from my post history I'm entirely capable do doing that. In fact if found the 60Hz solution for the flickering issue on this very tablet.
I can't provide further evidence of the grain issue as I don't own the tablet anymore. Other have also stated they can see it.

Colour preference is subjective. Real issues with image reproduction is not. The LG HDR video demo on YouTube was a good example where the brightly colour balls would show the issue quite easily.

I own the QDOLED Alienware 34" ultrawide a LG C7 and the P12 Pro. All of which I can watch media on and thoroughly enjoy the IQ. The P11 Pro would always leave me frustrated by the grain. The problem is not brand or cost influenced, its my eyes.

 

[Kajman]

Lenovo has problem with hdr in dark scenes or overall dark scenes?

 

[mardon85]

Lenovo has problem with hdr in dark scenes or overall dark scenes?

The black bars are not even black.
If a screen fades to black the whole screen glows slightly like a traditional lcd. The black floor is too high.

 

[Kajman]

It is a pity. But imagine that I have Xiaomi Pad 5 and there. when HDR/Vision applies screen is... too black And that is ips Strange world nowadays bad blacks on oled, too deep on lcd I hope my Y700 comes with HDR/Vision working properly. I am still looking at P12 Pro, but don't know how will support work, I have some bad experience with taht after some old Yoga.

 

[mardon85]

It is a pity. But imagine that I have Xiaomi Pad 5 and there. when HDR/Vision applies screen is... too black And that is ips Strange world nowadays bad blacks on oled, too deep on lcd I hope my Y700 comes with HDR/Vision working properly. I am still looking at P12 Pro, but don't know how will support work, I have some bad experience with taht after some old Yoga.

Annoying isn't it. Do they not test these things before releasing them.
The other option is Samsung Tabs but they don't support Dolby Vision annoyingly.

 

[Kajman]

And are full of bloatware and cost twice as those, but you pay only for brand, thay are not twice better.
Anyway xiaomi and lenovo have same ****level customer care and service.

 

[DaneLaw]

The black bars are not even black.
If a screen fades to black the whole screen glows slightly like a traditional lcd. The black floor is too high.

Annoying isn't it. Do they not test these things before releasing them.
The other option is Samsung Tabs but they don't support Dolby Vision annoyingly.

It's so easy too jump to conclusions, and not do your own due diligence..

no doubt Lenovo FW leaves a lot to be desired, but the hardware is top nudge not least with the price in mind - and so is this 1600p RGB OLED panel Lenovo is using - as you can also see on Notebookcheck, where this panel tops the charts amongst all OLED tablets and also better than E4 and E5 AMOLED.. the only other model that can match its color check scores - is Ipad Pro 12.9" 2021 with its MiniLED, as I showed above with the pasted values.

This "LCD glow" you keep referring to that you encounter/encountered..- can often be down to other things, that have nothing to do with this product, but third-party aspects you are pushing on the item..
like numerous custom ROMs, third-party apps.. or simply the HDR container-.. where static HDR or dynamic HDR data does not play along with the app you are using and the black floor ain't referenced.

Also why its usually preferred to cut away as many chains in the link as possible, if you wanna decipher the reason for a possible issue your experiencing- and get it as native as possible to sense which factors are causing problems and if its fundamental?
This is what I have tried to show you in the pursue to help you, get to the root of your problems, not least with direct greyscale grading directly to a display app with finer and finer lines to black' as if there is a problem with the grading it will show itself, but it was ideal., and where you stated that you would make a video showing it, but you never did, and fair enough, you do you.

If anybody is experiencing it, then try to take some of the promo OLED HDR vids, from Sony, LG, Samsung, etc. (don't use Youtube) - take them down natively in their TS codec.
Here is an example with P11pro2021 natively. (YT below)
The unit has not been through the wringer with different custom-ROMs back and forward - at any time, came with the native CN/ENG with OTA ability and this video is with the FW it arrived with.

Here playing an OLED promo vid, (the LG OLED with the pencils) that I was stunned by when I first got my 7'serie LG OLED TV back in 2017.
Its called"LG OLED Art HDR UHD 4k Demo".. (469MB) Link:

LG: OLED Art HDR UHD 4K Demo | 4K Media

LG OLED Art is a promotional video, in Ultra-HD HDR, for LG 4K TVs. Video Info: Resolution: 3840 x 2160 File size: 406 MB Duration: 00:01:21 Format: TS Codec: HEVC Frame rate: 60 fps

4kmedia.org

Played from ext. M.2 SSD with MX Player Pro app on P11pro2021.
and you can clearly see the "black" is inky black, and completely summons with the bezels.
(example on P11pro2021 in 4K)