May be time to collect a logcat
- https://doc.e.foundation/support-topics/create-a-log.html
- [HOWTO] Create a log (a bug report) easily without computer
Either method, I would suggest with Advanced Privacy fully off, all other running apps closed before fully shutting down with full 15 second press of Power button.
Then start the device and test the app. Collect the log soon after the fail, note the time accurately at notable points in the test. https://paste.tchncs.de/ uaually wotks nicely.