After updating and building APKs with Visual Studio 2019 (16.2.0, Xamarin.Android 188.8.131.52), we have started receiving reports that our icons were different or changing over time within our Android apps.
I was able to look at a few different devices, and could confirm that the icons were definitely changing. I've attached a "Correct" example, and an "Incorrect" example.
The devices always start with the correct icon set, but they will eventually switch and start using a "random" set of icons instead - although they are existing icons within the app. Every icon changes within the app. The problem persists, even if you force close the app. It's almost as if the resource IDs are switched or changed, and then cached - but since they are automatically generated, our app has no direct control over that.
The icons can be switched back to the correct set by restarting the device, or by reinstalling the APK from the app store - however, over time the app will go back to the incorrect set - and stranger still, it will be the same incorrect icons ("pin" becoming "box", "white refresh" becoming "black refresh", etc).
I cannot find a cause for why this is happening, because I cannot reliably reproduce the issue. I suspect that it is caused when app is suddenly or unexpectedly closed, but this does not happen every time. I've seen this happen in debug builds, as well as release builds.
This issue does not occur if the APKs are built with Visual Studio 2017.