Convert T-Mobile to International (with Bootloader Re-LOCK)

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this_is_nick6

Senior Member
Apr 18, 2011
82
61
31
Halifax
OnePlus 8
First I need to make sure the update works. The Global rom comes directly from the OnePlus website for the 8. The video I linked most likely will not work with US branded phones. With an unlocked bootloader, you cannot receive updates from Android updates. I am going the fastboot route when I get my unlocked token.

My question is can I simply flash the global rom via fastboot straight across via Android SDK platform tools without reverting to an Android 10 rom.

The Android 11 Global rom is newer than the latest T-Mobile Android 11 rom.
I tried this and got the Qualcomm crashdump error. I had to use the MSM tool and revert to the older (Android 10) T-Mobile software in order to convert to Global.
 

blair.sadewitz

Senior Member
Dec 24, 2014
246
53
I have no issues with the MSMTOOL, bricking my device and unbricking it. The video on page one, he gets into fastboot mode using the menu on his phone. There is another guy on youtube who gets into fastboot by using a fastboot bootloader in the command prompt. I use the volume up and down buttons plus the power button to get into fastboot mode.

I hear your suggestion on the flash all bin file. I am going to try a different machine, different unzip tool and different USB ports and cables.

I was assuming there is no right or wrong way to get the phone in fastboot mode. Is this assumption true?
There are two fastboot modes, fastboot and fastbootd, but this probably isn't the issue. Fastbootd is implemented in userspace. I believe their end goal is to unify recovery and bootloader, moving them into the boot image.
Flashall is the recommended way to do it by the authors.

There is no wrong way to get into fastboot mode. ;-)


Msmdownloadtool doesn't use fastboot at all. It uses Qualcomm's "emergency download mode" ("firehose"). This is entirely different. In this mode, the phone is barely alive. Modern Qualcomm phones are unbrickable. You could write /dev/random to the protected partitions and recover it--assuming you have all the information/images/etc you need. There is nothing you could possibly do to the hardware aside from throw it out your window or something to truly kill it. It's a shame so many manufacturers are dead set against consumers being able to repair their own devices. Just one more way to sell more phones ...
 

blair.sadewitz

Senior Member
Dec 24, 2014
246
53
I tried this and got the Qualcomm crashdump error. I had to use the MSM tool and revert to the older (Android 10) T-Mobile software in order to convert to Global.
This is misinformation re: updates. I don't know where it came from, but lots of people apparently believe that you cannot take updates with an unlocked bootloader. It's simply incorrect. You can't take INCREMENTAL updates, but the built-in updater will happily download full images.
 

blair.sadewitz

Senior Member
Dec 24, 2014
246
53
I tried this and got the Qualcomm crashdump error. I had to use the MSM tool and revert to the older (Android 10) T-Mobile software in order to convert to Global.
I really want to know why this happens. It's really getting in the way of my ROM flashing addiction to have to do all that extra flashing haha.

I think it should be possible to roll our own global firmware package to flash in edl mode. At the very least, I think we should be able to do the upgrade procedure, relock the bootloader, then dump the partitions using edl mode. Everyone could just use their own backups to restore, and it would make things a lot simpler.
 

dlhxr

Senior Member
May 26, 2011
544
508
New York City
OnePlus One
OnePlus 3
I really want to know why this happens. It's really getting in the way of my ROM flashing addiction to have to do all that extra flashing haha.

I think it should be possible to roll our own global firmware package to flash in edl mode. At the very least, I think we should be able to do the upgrade procedure, relock the bootloader, then dump the partitions using edl mode. Everyone could just use their own backups to restore, and it would make things a lot simpler.
how do you deal with the qdl to flash images to op8?
 

Two Sheets

Member
Jan 11, 2022
37
7
1
yeah, I did the same, but the seond sim still not working. It's not the IMEI that blocks the dual sim. We need to see what further we can do...
You need an international version of the OnePlus 8 to get the dual sim to work. The NA version does not support it. Handsets are not just regional, they have
There are two fastboot modes, fastboot and fastbootd, but this probably isn't the issue. Fastbootd is implemented in userspace. I believe their end goal is to unify recovery and bootloader, moving them into the boot image.
Flashall is the recommended way to do it by the authors.

There is no wrong way to get into fastboot mode. ;-)


Msmdownloadtool doesn't use fastboot at all. It uses Qualcomm's "emergency download mode" ("firehose"). This is entirely different. In this mode, the phone is barely alive. Modern Qualcomm phones are unbrickable. You could write /dev/random to the protected partitions and recover it--assuming you have all the information/images/etc you need. There is nothing you could possibly do to the hardware aside from throw it out your window or something to truly kill it. It's a shame so many manufacturers are dead set against consumers being able to repair their own devices. Just one more way to sell more phones ...
I completely agree with you on the MSM tool. It's bullet proof and works every time. I did get everything figured out. I had it right all along. The issue was the USB drivers. It may have been the windows drivers instead of the drivers in the download package. It was like throwing a wrench at my computer and it suddenly worked right. Makes no sense. Anyway, I have the global version and it's updated to Android 11 with the bootloader locked.

I used two different desktops. The one that failed was the computer that worked in the end.
 

Two Sheets

Member
Jan 11, 2022
37
7
I tried this and got the Qualcomm crashdump error. I had to use the MSM tool and revert to the older (Android 10) T-Mobile software in order to convert to Global.
They say if you get a crashdump error, you have the wrong files for the phone that you were trying to install. Even if you have right files for the phone. The crashdump error occurs when the wrong files are trying to be installed. I think the Global OS Android 10 route is the best way to get the global rom on your phone via the stock T-mobile Android 10 rom.
 

this_is_nick6

Senior Member
Apr 18, 2011
82
61
31
Halifax
OnePlus 8
They say if you get a crashdump error, you have the wrong files for the phone that you were trying to install. Even if you have right files for the phone. The crashdump error occurs when the wrong files are trying to be installed. I think the Global OS Android 10 route is the best way to get the global rom on your phone via the stock T-mobile Android 10 rom.
Yeah, I tried to take a shortcut and go from T-Mobile Android 11 to Global Android 11 because logically you’d think that would work… but I ended up with the crash dump error.

When I reverted to T-Mobile Android 10 I was able to convert to the global version of Android 10 successfully. I made some adjustments to the process along the way which I’ve detailed in an earlier post.

Something I did not test, was updating straight to the latest global version once converted and trying to lock the bootloader without going the Euro OTA route. I think that’d be worth testing to see if the bootloader lock on Global still bricks the phone.
 

dlhxr

Senior Member
May 26, 2011
544
508
New York City
OnePlus One
OnePlus 3
Just for simplification and update what I have done to convert:
1. Msmdownloadtool to OnePlus_8_T-Mobile_OxygenOS_10.5.22. (Can be found on onepluscommunityserver)
2. Unlock bootloader and flash fastboot oxygen rom: https://forum.xda-developers.com/t/rom-stock-fastboot-op8-stock-fastboot-roms-for-oneplus-8.4084629/. I use 10.5.9-Europe
3. Reboot into system and flash the same version zip rom using local update. 10.5.9-Europe official zip rom: https://otafsg1.h2os.com/patch/amaz...gen_15.E.18_OTA_018_all_2007160043_913306.zip
4. Reboot after flashing the zip rom and then flash the same zip rom again using local update in order to make sure all slots are offical EU rom.
5. Now you can lock the bootloader.

So to summarize, after you convert by fastboot rom, flash the offical zip twice using local update and then you are good.
 

BladeRunner

Senior Member
Jan 15, 2012
1,452
392
Has anyone done this and successfully got data/voice working on U.S. T-Mobile? I've gone through this probably 3 times now and always wind up with the "Sign in to Network" notification. The phone sees the SIM and recognizes the number but apparently it doesn't register on the network. This SIM works fine other phones.
I am on 11.0.10.10.IN21AA with a re-locked bootloader.
 

Two Sheets

Member
Jan 11, 2022
37
7
Has anyone done this and successfully got data/voice working on U.S. T-Mobile? I've gone through this probably 3 times now and always wind up with the "Sign in to Network" notification. The phone sees the SIM and recognizes the number but apparently it doesn't register on the network. This SIM works fine other phones.
I am on 11.0.10.10.IN21AA with a re-locked bootloader.
I have the OnePlus 8 with Global Rom on T-mobile network working fine. For Verizon, I am waiting on a 5G sim. I have a 4G LTE but Verizon is running their MMS and text messages through the CDMA network still. So it sits on the T-mobile Network, get a 5G signal with it.
 

ktang712

Member
Feb 18, 2019
6
2
Hi there,

Sorry, but I'm having trouble following your tutorial.

In step 1, what do you mean by "First install the Drivers of the phone and the Qualcomm Drivers inside the attached file after downloading it at the bottom of this guide."? I can't find the qualcomm drivers. Are the files you're referring to titled "TOOL_ALL_IN_ONE_1.1.1.6-NO-INSTALLER.zip" and "DRIVERS.zip"? What should I do after extracting them? What is meant by installing them?

I tried to unlock my bootloader using this link you provided: https://www.oneplus.com/support/answer/detail/op588. In that guide, I'm at the step where it tells me to type in cmd "fastboot.exe oem get_unlock_code". After I type that, cmd says "< waiting for any device >". That's where I'm stuck. What should I do?

Thanks

PS is there another way you prefer to communicate? Maybe like an instant messenger? It would be quicker if you don't mind.
 
Last edited:

Scout12345

Member
Jan 27, 2018
8
3
I managed to successfully convert my OP8 to the global version this morning.

Here are a few things I can confirm:

- 5G and VoLTE are working on my device (Rogers network in Canada)
- Banking apps work as expected
- Widevine certification is exactly as it was prior (L1), meaning I can stream in full HD/HDR with Netflix
- I was able to OTA update to the latest 11.0.10.10 without any issues at all

My first attempt trying this was a month ago. I was lazy and didn't roll the phone all the way back to Android 10 using the MSM tool. So I tried using "flash-all" with a newer global package and it did not work (crashdump error). Figured it was worth a shot... for whatever reason it just doesn't work. Ended up restoring with the MSM tool.

This time, I did this:
  1. Reverted back to official T-Mobile Android 10 using the MSM tool
  2. Unlocked my bootloader using the all-in-one tool + my unlock token
  3. Used the all-in-one tool to flash the global fastboot ROM (Android 10) linked in the original post
  4. Manually flashed the EU update from the device (also linked in original post)
  5. Locked the bootloader using the all-in-one tool
  6. Used the Oxygen Updater app to download the latest global full release (11.0.9.9) and installed it from my device
  7. Performed an OTA update, bringing me to 11.0.10.10
Sorry for the long post. I thought it might help someone else out since I modified a few steps from the original post and found success with this approach.
Question on step 4. I have downloaded both ROM's to PC and about to flash the Global using the all in one tool. I am a little confused on how exactly you manually flashed the EU update. Can you provide baby steps here? Did you reboot after the Global Rom install, minimally set up, re-enable Developer Options and USB debugging, transfer the EU Rom (from PC) to some location on the phone? And if so, how did you install it from there? Also, I took a look on my installed TMo ROM (10.5.7) , under Settings/System/Update and don't see a gear in the top right to choose installing from a Local Source. Is this something that will show up on the Global ROM? Thanks for helping out this novice!
 

Mickey1987

Member
Nov 20, 2021
8
2
Hi there,

Sorry, but I'm having trouble following your tutorial.

In step 1, what do you mean by "First install the Drivers of the phone and the Qualcomm Drivers inside the attached file after downloading it at the bottom of this guide."? I can't find the qualcomm drivers. Are the files you're referring to titled "TOOL_ALL_IN_ONE_1.1.1.6-NO-INSTALLER.zip" and "DRIVERS.zip"? What should I do after extracting them? What is meant by installing them?

I tried to unlock my bootloader using this link you provided: https://www.oneplus.com/support/answer/detail/op588. In that guide, I'm at the step where it tells me to type in cmd "fastboot.exe oem get_unlock_code". After I type that, cmd says "< waiting for any device >". That's where I'm stuck. What should I do?

Thanks

PS is there another way you prefer to communicate? Maybe like an instant messenger? It would be quicker if you don't mind.
Post in thread 'UPDATE: OnePlus 8 IN2017 T-Mobile to International (with Bootloader Re-LOCK)' https://forum.xda-developers.com/t/...with-bootloader-re-lock.4345305/post-86337021
 
Hi there,

Sorry, but I'm having trouble following your tutorial.

In step 1, what do you mean by "First install the Drivers of the phone and the Qualcomm Drivers inside the attached file after downloading it at the bottom of this guide."? I can't find the qualcomm drivers. Are the files you're referring to titled "TOOL_ALL_IN_ONE_1.1.1.6-NO-INSTALLER.zip" and "DRIVERS.zip"? What should I do after extracting them? What is meant by installing them?

I tried to unlock my bootloader using this link you provided: https://www.oneplus.com/support/answer/detail/op588. In that guide, I'm at the step where it tells me to type in cmd "fastboot.exe oem get_unlock_code". After I type that, cmd says "< waiting for any device >". That's where I'm stuck. What should I do?

Thanks

PS is there another way you prefer to communicate? Maybe like an instant messenger? It would be quicker if you don't mind.
sorry i updated the thread now and yes its inside the drivers zip, u need the drivers for the phone to register as a plugged in device in fastboot and msm tool
 

Scout12345

Member
Jan 27, 2018
8
3
Question on step 4. I have downloaded both ROM's to PC and about to flash the Global using the all in one tool. I am a little confused on how exactly you manually flashed the EU update. Can you provide baby steps here? Did you reboot after the Global Rom install, minimally set up, re-enable Developer Options and USB debugging, transfer the EU Rom (from PC) to some location on the phone? And if so, how did you install it from there? Also, I took a look on my installed TMo ROM (10.5.7) , under Settings/System/Update and don't see a gear in the top right to choose installing from a Local Source. Is this something that will show up on the Global ROM? Thanks for helping out this novice!
Okay, replying to my own post here (sorry!) but hoping someone else might respond? I was able to install the Global ROM, and then download/install an update to it. Someone in another thread indicated that the EU install was not required before re-locking the bootloader, but I would like to get just a little more confirmation before I give it a try. Also, how important is it really to re-lock the bootloader? I know there is a bit of a security risk, but is it really that risky? It seems like the bootloader on my original OPO (way back when) was never re-locked...
 
Okay, replying to my own post here (sorry!) but hoping someone else might respond? I was able to install the Global ROM, and then download/install an update to it. Someone in another thread indicated that the EU install was not required before re-locking the bootloader, but I would like to get just a little more confirmation before I give it a try. Also, how important is it really to re-lock the bootloader? I know there is a bit of a security risk, but is it really that risky? It seems like the bootloader on my original OPO (way back when) was never re-locked...
-i have tried it a few times relocking it on global but i always get corrupted and i found out that euro is the safest way to relock bootloader but i have heard some ppl say they have done it on global but just to be on the safe side, id recommend go for the eu relock method.

-relocking the bootloader will restore l1 if u lose it-l1 lets u watch videos in full hd quality and safetynet- for some apps and normally for banking apps to work, makes device play certified.
 
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  • 1
    yeah in my experience on oos 12 but it was gone after c.16
    Thanks for the quick response. I'm on IN2015_11_C.16 as well. Hopefully it goes away after the next update.
    1
    yikessss, can you backup everything and maybe downgrade to oos 11?
    I'd probably have to msm back to T-Mobile software and decide if I want to try converting to global again... Ugh... PITA!

    I just looked at my info and for some reason it says I am still on c.16, but I know I had told it to install c.20, so something is borked up....

    Cheers,
    B.D.
  • 11
    The required files will be attached in the end of this guide.
    OnePlus 8 TMobile to Global Fastboot ROM
    MSM TOOL for IN2017

    Alternatives from the files above, if you get errors every time you are trying to flash like "NO SIM INSTALLED"
    (THIS IS WHAT I PERSONALLY USE):
    MSM TOOL for IN2017 Alternative
    OnePlus 8 Fastboot ROM Alternative

    1st Step: (Make sure Test Mode is ON and Driver Signature is OFF)
    First install the Drivers of the phone and the Qualcomm Drivers inside the DRIVERS.zip attached to this thread.

    2nd Step: Make sure your OnePlus 8 IN2017's bootloader is unlocked- unlocking bootloader will result to factory resetting your phone. Please backup your phone before doing this process. Instructions on how to unlock

    3rd Step: After the bootloader is unlocked, you have to enable "USB Debugging" and reboot your device to Fastboot Mode.

    4th and Last Step: Unzip the ZIP file and Open the Global Rom (10.5.12 OnePlus 8 Global Rom). Find flash-all.bat and double click on it. Type and enter Y when it asks to and just let it do its Terminal Process.

    **After the batch file is done, your phone should automatically boot to Global Rom Oxygen OS and no more of that T-Mobile
    splash screen.

    This is a YouTube walkthrough video on how to do it: Credits to Fizzy Apps on YouTube


    DO NOT LOCK YOUR BOOTLOADER YET, TO LOCK BOOTLOADER (THIS WILL WIPE EVERYTHING):
    -Download the latest OxygenOS 11 ROM
    -Move the downloaded ROM from "Downloads" folder to "Internal Storage"
    -Go to settings and find System Update, then press Local Update and choose the downloaded ROM
    -After its done installing, click REBOOT/Restart the device
    -After rebooting, go into FASTBOOT MODE and when you are in FASTBOOT MODE, type "fastboot oem lock"
    -Press the volume buttons to select LOCK BOOTLOADER and there you go, LOCKED Bootloader!

    IF SOMEHOW YOU GOT "QUALCOMM CrashDump Mode" during the 4th step or you locked Bootloader right after flashing ROM and it got corrupted.

    1) Enable Test Mode and Disable Driver Signature Verification on Windows PC.

    2) On your phone, simultaneously press and hold Volume Up (+) and Power Button and when the screen shuts down, IMMEDIATELY release both buttons. This means you forced shutdown the device.

    3) Set year date on your PC to 2017 and Turn off WIFI for MSM Tool to work and after doing this, open MSM TOOL folder you downloaded at the top of this guide and click MsmDownloadTool V4.0.exe

    4) On Login, set user type to "OTHER" and click next. at the top left side find "TARGET" and set it to O2/TMO

    5) While simultaneously holding both the volume buttons, connect the phone to the PC. As soon as the phone is connected, a COM# like COM3, etc. will appear on the MSM Tool and immediately click ENUM, then click COM#, then Start. (If COM# doesn't show up just continue to click the ENUM button during process and it should show up)

    <A YouTube Video walkthrough of this process> Credits to Shahin Shaan for this.

    **This should start the process of restoring your phone back to OxygenOS 10 and you have to start back to square 1 in order to flash Global ROM again. So, USB Debugging>Fastboot Mode>Unlock Bootloader>Enable USB Debugging Again>Boot again to Fastboot>Double Click on flash-all.bat on Global ROM folder. Also, I added TOOL ALL IN ONE which should make unlocking bootloader, booting to Fastboot faster.



    Credits to these amazing people for making this possible:

    @matteosaeed and his Guide.
    •Ms. user_ajusee's Guide
    •Mr. gregoryaul (@Aulgreg38) from HighOnAndroid Forums
    •THE MAN HIMSELF: Mr. Max Lee himself of HighOnAndroid Forums; link to his YouTube channel.
    10
    I tried again, MSM to 10.5.7, unlocked bootloader, rebooted to bootloader, flash-all.bat, and I'm still getting errors on the critical partitions. And I can't figure out how to unlock the critical partitions (probably not allowed in TMo firmware).

    I'm going to MSM to 10.5.22 and see if that makes any difference.

    EDIT: No dice. 10.5.22 made no difference. The issue is the locked critical partitions. If anybody has any solutions please tag me.
    Sorry for spamming the board today, but I think I figured it out.

    Thanks to @thattechguy_69 for all the work here so far. This is just to help anybody who is having issues like I did.

    The "critical partitions" issue appears to be a DRIVERS issue, not a fastboot version issue or anything else with the actual phone or ROM files. I had installed all of the drivers that every guide said to install, but I stumbled upon this post by @FoxyDrew that solved my issue.

    Here's how I finally got into 10.5.12.IN21AA (Global ROM) on my IN2017:

    1. Just to be safe (not sure if it's necessary) boot into TEST MODE on your Windows machine. I did all of this from Test Mode.
    2. Download the files from the zip attached at the bottom of the first post on this thread. Install both files (OnePlus USB Drivers and QDLoader HS-USB Driver).
    3. At some point I THOUGHT I installed the Fastboot drivers, but maybe I messed that part up or maybe it was before I was in Test Mode. Regardless, download the Google fastboot driver zip in this post. Unzip it to your desktop.
    4. Open the extracted folder and then the usb_driver folder inside, then right-click on the android_winusb.inf file and select Install. Confirm the installation.
    5. Plug in your phone.
    6. Open Device Manager. Your phone should show up under "Universal Serial Bus controllers" as "IN2017" when it is in CHARGING ONLY mode, and under Portable Devices when in File Transfer mode or PNP mode. If not, you'll need to fix your USB drivers from step 2 above.
    7. Make sure you can get adb commands to work, then reboot to the bootloader ("adb reboot bootloader" should get you to the FastBoot Mode menu with the big green "START" banner at the top) and make sure fastboot commands also work ("fastboot devices" will show you if your phone is detected properly).
    8. Check Device Manager again while in bootloader mode - your phone should now show up under "Android Phone" as "Android Bootloader Interface." If it shows up as IN2017 with an exclamation mark, you need to fix the issues with the fastboot driver in step 4 above. I actually did this step while at the "waiting for device" message while flashing the Global ROM and it kick-started the installation's second phase.
    9. I also followed some steps from this post by @awsan - I copied the entire platform-tools folder that I downloaded from his post (r31.0.2) into the 10.5.12-GLOBAL folder, replacing all duplicate files. I don't think booting into fastboot like he says to do (language selection splash screen) worked, I had to boot into the bootloader from there to get the flash-all.bat to start.
    10. From here, I think I just double-clicked the flash-all.bat and everything worked properly - with the note that I was stuck at "waiting for device" after the first reboot command in the middle of the installation. The process in step 4 got me through this.
    This fixed my issues with not being able to flash critical partitions (because I suspect they re-lock when fastbootd switches into bootloader if you manually do it). Now it doesn't hang at all. I am going to play around with this to make sure I didn't miss anything and see if it works with other TMo firmware versions and the newer 11.0 Global ROM.

    I have not tried locking the bootloader yet.

    Oh, and 5G and VoLTE both appear to be working.
    4
    I managed to successfully convert my OP8 to the global version this morning.

    Here are a few things I can confirm:

    - 5G and VoLTE are working on my device (Rogers network in Canada)
    - Banking apps work as expected
    - Widevine certification is exactly as it was prior (L1), meaning I can stream in full HD/HDR with Netflix
    - I was able to OTA update to the latest 11.0.10.10 without any issues at all

    My first attempt trying this was a month ago. I was lazy and didn't roll the phone all the way back to Android 10 using the MSM tool. So I tried using "flash-all" with a newer global package and it did not work (crashdump error). Figured it was worth a shot... for whatever reason it just doesn't work. Ended up restoring with the MSM tool.

    This time, I did this:
    1. Reverted back to official T-Mobile Android 10 using the MSM tool
    2. Unlocked my bootloader using the all-in-one tool + my unlock token
    3. Used the all-in-one tool to flash the global fastboot ROM (Android 10) linked in the original post
    4. Manually flashed the EU update from the device (also linked in original post)
    5. Locked the bootloader using the all-in-one tool
    6. Used the Oxygen Updater app to download the latest global full release (11.0.9.9) and installed it from my device
    7. Performed an OTA update, bringing me to 11.0.10.10
    Sorry for the long post. I thought it might help someone else out since I modified a few steps from the original post and found success with this approach.
    3
    Thanks for the guide!! I just submitted my request to T-Mobile to unlock my boot loader so now I play the waiting game... 😴
    In the meantime, can someone please clarify what does converting from IN2017 to International achieve? Ultimately my goal is to flash a custom ROM - not sure if I can do this directly after unlocking my boot loader.
    IN2017 is Tmobile version of the phone and updates are late and you cant sideload an update because it is not available on carrier versions of the phone. Converting it to International version gives access to the latest updates, and some other features that weren't available to Tmobile version. If you do this method, you will lose Safetynet which is the ability to use bank apps and etc. So after converting you have to lock the bootloader if you wish to do anything related to banking.
    3
    I am confused between this guide and the old one " Covert to Global ( WIP ) . Which one is best guide to convert OP8 TMO Android 11 to Global ?
    Should I back up/ change modem with this guide ?
    Is there diff between EU and Global ROM/modem/etc. to use 5G in USA and other oversea countries ?
    I want Always On Display ( AOD ) , which ROM EU or Global will have it ?
    TIA

    Yeah, it's not entirely clear to me, either.

    This is what you should do:

    (1) Put your phone back on Android 10 TMobile firmware using one of the packages with msmdownloadtool. I used 10.5.7

    (2) Unlock bootloader.

    (2*) Get TWRP boot image. Put phone in fastboot mode, type:

    fastboot boot twrpimage.img

    After TWRP boots, take a backup of your persist and modem partitions (I recommend using dd to do it, here's an example: dd if=/dev/block/boot device/by-name/persist of=/sdcard/persist.img.ext4). You could probably use TWRP to do the backup, but that's on you. Transfer them off of the phone and safeguard them.

    Now reboot from TWRP to fastboot mode. Unlock the bootloader, reboot to fastboot mode, and flash a 10.x euro or global ROM with fastboot. The guide says Euro, but I suspect you could use global, also. The goal is to have it running 10.x firmware (that's not for a carrier variant). After that boots, download the latest global OTA zip onto your internal sdcard. Open the updater in Settings, then select the file. After it updates, reboot to see if everything is OK. If it is, boot to fastboot and relock the bootloader.

    The