USB Connection seems to hang/disconnect randomly. OnePlus problem?

[poisike]

Firstly I would like to say that BMW needs to hire hufman!

I'm using a OnePlus 7 Pro with Android 11 and a NBT idrive 4 over USB. I'm mainly using AAIdrive for Spotify.

Everything works fine for about 10-30 minutes on first connection and then the idrive Spotify app display freezes (music continues over BT), I can't skip tracks, enter playlists/browse or do anything apps related, so it looks like the phone has disconnected, but the phone still thinks it's connected. To get it to work again, I have to select "File Transfer" mode on phone, this triggers My BMW app to reconnect and everything works fine again for another ~5 minutes. Interestingly the first connection of the day or after a phone restart seems to work for longer than the reconnects triggered by changing the USB mode on phone. Otherwise the time it works seems completely random.

It seems to me like either the My BMW app crashes in the background or the phone just kills My BMW app or the phone kills USB connection. Anyone else using AAIdrive with OnePlus phone on Android 11?

What I have tried so far:
Set AAIdrive app battery optimization to "Don't optimize"
Set My BMW app battery optimization to "Don't optimize"
Set Spotify app battery optimization to "Don't optimize"
Disabled adaptive battery completely in "Advanced optimization settings"
Set "Default USB configuration" in "Developer options" to "File Transfer"
Locked both AAIdrive and My BMW apps in recent apps hoping that they are not killed in that case
Tried leaving the My BMW app on screen before locking the phone
Tried different versions of BMW apps: BMW Connected Classic 1.8, BMW Connected 6.4.0, BMW Connected 6.4.1, My BMW 1.6.2
None of these things have made any difference, except I think with BMW Connected 6.4 the notifications still came through even after Spotify froze (but not 100% sure about that as I have tried countless combinations)

Anyone has any ideas what to try? Any idea how to troubleshoot what is actually causing the disconnect?

[hufman]

Thank you for the excellent debugging you've done!
I agree with your guess that MyBMW is being killed or otherwise suspended while it's in the background. You could test whether the connection seems to stay alive longer if the screen is kept on and showing the MyBMW app in the foreground.

The MyBMW app and the car have a watchdog process, checking with each other every few seconds to make sure they are still responding. After 30 seconds of no activity, the connection drops and the car cleans up any apps. You should see if the apps disappear from the car after 30 seconds or so, maybe 60 just to be sure, after you notice they have frozen.

Another test you could try is to force-kill AAIdrive during this frozen state: The AAIdrive>MyBMW connections will drop, and if MyBMW were still functioning, it will remove the app entries from the car at this time.

Let me know what you find out!

[poisike]

Thanks for the replay!

I checked and car does not clean up the apps list on it's own (I waited over 10 minutes). Apps stay in the list (Google, Alexa, Notifications icon, Audioplayer and one without a icon or text). Nothing happens if you click on them.
I force closed AAIdrive - nothing happened, car still showed the apps list
I force closed MyBMW - nothing happened, car still showed the apps list
I disconnected USB cable from phone and immediately apps disappeared from the list

Any other ideas what to try? I thought about trying another phone, I have a few OnePlus phones (all on Android 11) I can try and a old Nexus 4

[hufman]

Hmm very strange indeed! I'm not sure what else to try, besides trying the different phones (especially the Nexus).

[poisike]

I tried Nexus 5 and it worked just fine, no freezing.
I found I had a Oneplus 7T that I had not updated to Android 11 yet, so running Android 10. I tried with this phone and it froze within 5 minutes. As I couldn't believe the result, I realized I was using the same cable with Oneplus phones, so I tried with another cable and everything worked for about half an hour, didn't have time to test for longer today morning... Could it be that the cable was the problem? It's a short USB-C cable that I probably got with Nexus 6P.
I will report back when I had time to do some more testing.

[poisike]

Drove around for one and a half hours tonight just to test it more. I have no idea how this is possible, but using another cable fixed the issue, no more freezing, works without any issues with my OnePlus 7 Pro. Really happy!

Thanks hufman for making this possible!

[hufman]

That's so great to hear! I'm glad it's working for you, thank you for the compliments :)