@IzzyOnDroid The developer is working on a fix. I will observe this and tell you later.
from the developer:
"Hi. Firstly, I have absolutely no idea where you got that 0.53b package from. Symphonica is only released in my telegram group and this repository's GitHub release. I also don't know what is quake3-music. MD3 in the description means "Material Design 3", which is a unified design language and component library by Google. Perhaps you're mis understanding something here. ...
more:
"Also if you can't find any music in symphonica in Android 12, make sure you've upgraded your app version to 0.56b which contains backwards compatibility till Android 10."
@IzzyOnDroid
The app with the hotfix 0.56b works, but does not scan the sdcard.