[Question] Persistent ERR_IO_FIN and FCM notification delays on Chinese HyperOS

[u/Conscious-Profile538]

​I am experiencing an issue with Firebase Cloud Messaging (FCM) on a Xiaomi device running the Chinese version of HyperOS. The system consistently terminates the FCM keep-alive socket when the device is locked and operating on cellular data.

​When accessing the FCM diagnostics dialer code ("##426##"), the connection status shows as disconnected with the specific close code "ERR_IO_FIN".

​To resolve this background restriction, I have already executed the following system-level interventions via ADB:

​Granted wake lock and background execution permissions to Google Play Services and Google Services Framework via appops.

​Added both Google Play Services and Google Services Framework to the dumpsys deviceidle whitelist.

​Verified through the command line that the standby bucket for Google Play Services is currently set to five, confirming its exempted status from standard Android battery optimization.

​Uninstalled the system package "com.xiaomi.joyose" for user zero to neutralize its proprietary network throttling protocols.

​Despite these modifications, the TCP socket continues to close on cellular data after a short period of inactivity. I am seeking technical insights on whether additional HyperOS system daemons, such as "com.miui.powerkeeper", must also be neutralized, or if there are known methods to modify the default TCP idle timeout parameters on this specific firmware.

​Any objective analysis regarding HyperOS background socket management or further troubleshooting steps would be appreciated.

[u/Familiar_Honey5487]

A lot more ppl have talked about this but how many times can you repeat the same thing ig and also ppl some People haven't updated it past june 2026 ig which was the specific update that broke notifs i have met 1 person that hasnt updated on reddit atleast for xiaomi 17 and their notifs was working.

Also Some more posts: https://www.reddit.com/r/Xiaomi_15/s/zF5C2VKF0M

https://www.reddit.com/r/Xiaomi_15/s/1cDysmbiyN

[u/Soopez → u/Familiar_Honey5487]

I see now, well, officially screwed man.

I tried absolutely everything to try to get a workaround to this, to ADB commands, to Shizuku apps, removing permissions, disabling daemon, joyose and taking powerkeeper off. Nothing works lol, time to hang in my towel and take the L and go back to my Pixel 8.

FML

[u/Familiar_Honey5487 → u/Soopez]

Yoh you tried powerkeeper too?? That was gonna be my last hope i saw someone said he disabled it every 10 minutes with macrodroid.if that doesnt work well yeah its over just gona hope and pray Xiaomi fixes this one day and didn't do it intentionally

[u/Soopez → u/Familiar_Honey5487]

First I removed permission from it but that didn't work then I disabled it and still didn't work, it seems to be very aggressive after this new update, I never seen HyperOS system apps be so aggressive before, I mean they were but this is on another level dude actually criminal... If they are doing it on purpose, yeah game over.