Backup Restore Does not Work

Caynax Apps Caynax Sports Tracker
1

Restore function does nothing. No error messages. Version 3.5.1. Android 11.
I am trying to bring over history from my old phone by copying backup file over USB. Import of gpx tcx files does not work either. How to troubleshoot these issues?

2

Could you please mail me that backup file at caynax@gmail.com?