Unexpected behaviour in closing app on Android 16 devices on production released app

[gmck]

Android framework version

net10.0-android (Preview)

Affected platform version

VS 2026 Insiders

Description

My app displays unexpected behaviour when closing (quitting) the app, depending on whether the app is launched from the App Drawer or from the Home Screen. If closed after launching from the App Drawer everything is normal.

If launched from the Home Screen much of the shutdown code is not executing. My app is an OBDII app and this results in the Bluetooth Connection to the OBDII scan tool failing to close and an optional long running notification’s icon remaining visible in the status bar. The most obvious indication that there is something wrong is the app’s icon then has a bubble attached, whether viewed from the App Drawer or the Home Screen.

New behaviour in Android 16 is placing the last used app in the centre position of the 5 apps that appear above the Google search bar on the Home Screen. I think that is new behaviour because I don’t remember the above happening on an Android 15 devices and I now don’t have any devices running Android 15 to confirm. This feature seems to be different with the latest beta of Android 16 which places the icon in the 5th position of the 5 apps. With either, if you then pull down the Navigation Shade fully you will see at the bottom “1 app is active” and if you then click the right arrow, you get an Active Apps dialog explanation with a Stop button, which does the same as flicking an app out of memory. Either way results in the bubble being removed from the app icon.

If you always launch the app from the App Drawer, then the app closes as per the closing code and no bubble appears on the app icon.

There is no difference in behaviour if the app is built as net9.0-android36, net10-android36 or net10.0-android36.1.
What I can’t get my head around is why there would be any difference between launching an app from the Home Screen or the App Drawer. Why would they be different?

I’m attaching a couple of logcat logs, that demonstrate the closing code, or the lack of it in the homeScreenLaunch.txt. Each of these were created by making a connection to scan tool then clearing the logcat and then simply exiting the app and copying the output to the respective files.

I don’t believe there is anything with any of these builds from a net perspective that are causing the problem, but was hoping that you guys may have some ideas on how to correct it.

The other idea I thought about was to create a bug report at Android Open Source Project (AOSP) issue tracker.
However, I’m not sure if they would even accept issues for a net10-android36 app.

On the other hand, if you check issue #10304 I raised months ago and check the last entry it shows that they (or somebody) automatically picked up on the issue posted here and the link takes you to material-components/material-components-android#4883. I’ve got no idea how that seemed to be picked up from here by the guy who now claims it is fixed. If you view the submit details you can see the changes they made. The commit, till uses SetNavigationColor, SetStatusBarColor and SetFitsSystemWindows etc so I’m not sure how that was meant to fix it, which is what Google Play Console is still bitching about with every production release.

Steps to Reproduce

See above

Did you find any workaround?

No
appdrawerLaunch.txt
homescreenLaunch.txt

Relevant log output

[jonathanpeppers]

Are you able to share adb logcat -d > log.txt of a log that contains the error message? The logs above don't really show a stacktrace or what the problem is.

Is there a native/java/.NET exception/crash? If so, can you get the stracktrace/.ToString() that contains more info?

[gmck]

Hi @jonathanpeppers

The two files I sent were prepared with the following, as I was only interested in the closing (quitting the app) code.

The app was launched, and the Bluetooth connection with the OBD scanner tool was established, with the intention of just swiping the Connection fragment to exit the app. At that point, the following commands

adb logcat -c
adb logcat d -v time > homescreenlaunch.txt

Then the back gesture, wait a few secs, stop capture with Ctl+C,

findstr /R /C:"GLM - MainActivity" /C:"GLM - OBDService" /C:"GLM - OBD" /C:"GLM OBDServiceConnection" homescreenlaunch.txt > homescreenfiltered.txt

Repeat the above, but launch from the AppDrawer using appdrawerslaunch.txt and appdrawerlaunch-filtered.txt. Then I just renamed the filtered files to send here.

Both files start at startBackNavigation CurrentTask. The appdrawerlaunch,txt shows all the closing code, executing correctly. The homescreen version does not.

There is no exception in either.

The quitting process is started by OnSaveInstanceState of the MainActivity (a single Activity app)

if (!IsChangingConfigurations)
{
    if (((GlmApp)ApplicationContext!).CanCallFinish)
    {
        if (!((GlmApp)ApplicationContext!).AppBackGrounded)
        {
            // The ConnectionFragment i.e. the StartDestination fragment is the only fragment at this point. All the others have been popped already.
            // If the navController has nothing to pop it returns false and so we must call Finish(). 
            // The navController.CurrentDestination  e.g. the ConnectionFragment should now be null according to the documentation
            
            if (!navController!.PopBackStack())
            {
                Log.Debug(logTag, "MainActivity OnSaveInstanceState calling Finish()");
                Finish();
            }
        }
    }
}

What I can't figure out is why there is any difference in the execution of the shutdown code of an app, depending on where the app was launched from - the App Drawer or the Home Screen. As far as I can see, there is nothing new in the Android 16 documentation that indicates any differences between Android 16 and previous versions. I've been using the same code since Android 13, when they first introduced the Predictive Back Gesture.