• Introducing XDA Computing: Discussion zones for Hardware, Software, and more!    Check it out!
  • Fill out your device list and let everyone know which phones you have!    Edit Your Device Inventory

Xiaomi Redmi Note 9S Wifi stops working after leaving sleep mode

Search This thread

Segadorn

Member
May 16, 2013
21
1
I have buyed the new released Xiaomi Redmi Note 9S and i have problems with the Wifi. When you let the device to sleep for few hours wifi stops working. When turning on the phone from sleep the wifi dont work and you have to turn the wifi off and on to restore it, then i receive all the messages at once when the apps (Line, Whatsapp, etc) reconnect to inet. It seens to happen only if the device is sleep for few hours. If is only sleep for few minutes it works ok. Anyone experienced this issue, knows how to solve it?
 

Segadorn

Member
May 16, 2013
21
1
Mine is 11.0.3 global. When i awaked this morning and checked the phone it was working ok. No problems at all after all night in sleep mode. I am puzzled. I hope it was a "one" time fault and it works from now on. I come again if i have news.
 

DjXavy

Member
Apr 15, 2020
16
19
42
This also happens to my Redmi Note 9S.
It happens with all current ROMs. I experienced it with global, indian and eu ROMs.
Its also random, it does not happen after x hours. Sometimes its just 1 hour, others is 7 hours, others it does not happen.

What I do:
I turn off the smartphone screen to sleep, with wifi on. AC connected.
I have some apps reading internet data every 2 minutes.
When I wake up, I see the wifi icon connected. But Internet doesn't work.
When I look at the apps, I can see that they stopped accessing internet at a random time in the night.
If I turn wifi off and on, internet works again.
It doesn't happen with wifi off and mobile data connection on.
I tried changing some values in dev settings. Also in battery settings. Nothing has worked yet.
With normal day usage, it can also happens, if the screen is off a few hours.
It not a router wifi issue. My old note 3 worked fine with the same wifi. My wife's redmi note 8 pro works fine too.
It can be something related to battery saving. But so far I have been unable to fix if.
It never happens with screen on, or with screen off for a few minutes.
So I dont think its a hardware issue, I think its software-related.
 
Last edited:
  • Like
Reactions: wjzhweo

Segadorn

Member
May 16, 2013
21
1
This also happens to my Redmi Note 9S.
It happens with all current ROMs. I experienced it with global, indian and eu ROMs.
Its also random, it does not happen after x hours. Sometimes its just 1 hour, others is 7 hours, others it does not happen.

What I do:
I turn off the smartphone screen to sleep, with wifi on. AC connected.
I have some apps reading internet data every 2 minutes.
When I wake up, I see the wifi icon connected. But Internet doesn't work.
When I look at the apps, I can see that they stopped accessing internet at a random time in the night.
If I turn wifi off and on, internet works again.
It doesn't happen with wifi off and mobile data connection on.
I tried changing some values in dev settings. Also in battery settings. Nothing has worked yet.
With normal day usage, it can also happens, if the screen is off a few hours.
It not a router wifi issue. My old note 3 worked fine with the same wifi. My wife's redmi note 8 pro works fine too.
It can be something related to battery saving. But so far I have been unable to fix if.
It never happens with screen on, or with screen off for a few minutes.
So I dont think its a hardware issue, I think its software-related.

Thank you DjXavy, your post is perfect to describe my issues. As anyone triying to contact Xiaomi about this problem? Are they even aware of it?
 
Last edited:

DjXavy

Member
Apr 15, 2020
16
19
42
It could be a drivers or firmware problem. Xiaomi should be able to fix it.

What can we do:

1) If it happens to you too, please report it here and give details if you can. That way, Xiaomi can evaluate how common the problem is.
2) While it get fixed: Do someone know an app, or can build one, that check every few seconds if internet conection is working, and if it fails a few times, the app turns wifi off and on? It will require a rooted smarthphone to control wifi switch.
3) Do someone know how to send bug reports to Xiaomi? It would be good is they get a link to this thread.
 
Last edited:

Segadorn

Member
May 16, 2013
21
1
I have updated to 11.0.5 now, lets see if its fixed or not. I have used the inbuilt report feature in the phone to report the issue but anything else except this post.
 

KnightAtNight

Member
Nov 28, 2018
13
2
Xiaomi Mi A2
Xiaomi Mi A3
I may found the cause and workaround to prevent this bug.

Normally WiFi recognizes absence of internet connection. But in our case we're still online and I noticed some syncs still working. So DNS is coming to my mind. But I still changed my wifi to static IP using Google 8.8.8.8 DNS.

With Pie(?) Google introduced "Private DNS". I remember in MIUI 10 this feature was hidden and by default "off". On my NOTE 9S (global MI version) this setting was set to "Automatic" by default. After turning it off while dysfunctional WiFi, internet was coming back right away. After this (still) continuous connection.

The time is too short to be sure it's gone forever (*evil laugh*), but you guys could help to test.

You find the option in "Settings | Connection & sharing | Private DNS".
 
  • Like
Reactions: puoria

DjXavy

Member
Apr 15, 2020
16
19
42
Good work. Continue trying things!
I switched off that same option days ago.
My 9S still have problems with wifi.
Sometimes, even switching the screen off a few minutes is enought to trigger it.
I'm still trying things, but no luck so far.
 

skezza

Senior Member
Sep 29, 2007
1,485
191
Although I've only had it for one day, I've not seen this problem yet. Wonder if it's a Wi-Fi compatibility issue or something strange?
 

Urmelausmall

Member
Apr 15, 2017
26
4
Xiaomi Poco X3 NFC
I have noticed that I dont have problems when I am connected to a 802.11n network. The last Days I have had the Problems I Was connected to 802.11ac (2,4ghz + 5ghz). Today I was connected to an old 802.11n network and everything seems to be okay. Do you have the Problems with both Networks?
 
  • Like
Reactions: DjXavy

DjXavy

Member
Apr 15, 2020
16
19
42
I have noticed that I dont have problems when I am connected to a 802.11n network. The last Days I have had the Problems I Was connected to 802.11ac (2,4ghz + 5ghz). Today I was connected to an old 802.11n network and everything seems to be okay. Do you have the Problems with both Networks?

Interesting. I'm connecting to a 802.11ac wifi too.
I will switch to a 802.11n one and see what happens.
 

Top Liked Posts

  • There are no posts matching your filters.
  • 4
    Can you share with us how you did the hack in MacroDroid? It'll be very helpful :)
    Done, it restart the wifi every 15 minutes. You'll didn't notice it
    2
    seems to be solved with 11.0.3 on my phone

    Hey,

    it seems to be solved with MIUI 11.0.3 on my phone (fingers crossed).

    Here is what I did:
    Because of the fact, that there is no other OTA update per default than 11.0.1 for my phone (yet), I had to download it from
    https://c.mi.com/oc/miuidownload/detail?device=1900378 (can't link it due to "new user status")
    I live in germany and thought I should have a "Redmi Note 9 Pro global" Rom, but the Update process told me about "a different radio version". So I took V11.0.3.0.QJZEUXM which is for the EEA Version (no idea what EEA stands for; bought my phone directly from mi.com/de).
    To install it, I had to go to "settings - my device - system-update" and klick the "11" multiple times (like 5-10 times), since it says something like "additional update options enabled". Now you can klick "the three dots - choose update package" and choose your downloaded file.
    After the system checked if it's the right one, you can install it by a klick.

    I didn't root my device or something like that, the updateprocess is (as I believe) identical to an OTA Update. The packages is directly from mi.com, so I wasn't afraid of installing it ;)

    I'm running this version since yesterday afternoon, with no Wifi issues so far (fingers crossed again) an no forced reboots.

    Hopefully this may help you ;)

    greetings
    Ralf
    2
    In these days i were in contact with xiaomi assistance for this issue. I passed them several logs and did some tests. Today they said me that it is ready a test version that solves the problem and they will pass me it in these days
    2
    Is root necessary? Thanks for your work.
    Nope and I've switched to using MacroDroid now as Hotspot mode isn't supported in Automagic but works fine in MacroDroid (different reason). So both are good for this.

    Unfortunately, the update seemed to work for 2 days but was a false positive. It happened again today. I tried a different experiment, I used Allcast to torrent and play a film at the same time (cool feature on Allcast) and it worked fine despite sleeping for 2 hours. It's definitely some bug in the low power or low usage mode. I am sure they'll fix it soon.

    For now the Automagic/MacroDroid hack fixes it.
    2
    The dirty hack I've posted above hacks it. To be clear, not a fix... very much a hack.

    T6K1qo8.jpg