XDA Developers discovered a new app auto-hibernate feature that automatically deletes temporary files and cached storage for unused apps. The feature also retains the auto-revoke functions of Android 11, which automatically revoke privileges for unused apps.
https://www.notebookcheck.net/Android-12-includes-auto-hibernate-feature-for-unused-apps.533411.0.html
This better be something you can disable, ideally globally and per-app.