If I create an APK using flutter build apk, I can install and run my Flutter application (which is more or less the basic app template with a few charts added), but if I follow the steps to publish the Android app using flutter build appbundle, and add it to an internal test in Google Play Console, then everything is smooth (signing works, the Google Play Console "real devices" tests run without errors) until I try to install the app; here, I'm told that my devices are compatible (and indeed they show up as compatible on the very long list on Google Play Console), yet I'm told that "This app is not available for your device".
Other testers in the same geographical region (and, again, the automated "real device" tests) can install the app just fine, so it's not something fundamental about the app, and probably not Flutter's fault, so what can be the cause of this?
I've cross-posted this question as a Flutter GitHub issue.