During development, I used Google Play Games in the test mode.
Everything used to work fine, as expected. I had added my devices as testers as the project wasn’t published. All tests were done by compiling the app into an APK.
Once I finished development, I sent my game out for beta testing. No one reported any issues related to sign-in.
Last week, I finally uploaded the app on Play Store. Before uploading, I had published my Google Play Games project. After that I compiled my app as an APK, for one final test before the upload on Play Store. All was good. So I compiled the app as an AAB and put it on Play Store.
Yesterday, my app got approved. I downloaded the app, but the sign-in wasn’t working. A shadow appears (the one that we see when the account picker pops-up) and immediately goes away.
Today morning, I again compiled the app as an APK to check if something had gone wrong, but everything was working very well.
So I assume this is a problem with the compilation of the app into an AAB?
Tested on Android 10 and Android 8.1.