The nature of the issue points to software. There's not much a user can do to test but a few things come to mind:
- Test with Bluetooth OFF
- Test with wifi OFF
- Backup and test after Restore as new
If the behavior exists after a restore as new then it would seem there's some sort of corruption somewhere that goes away until you restore from a backup...or...a combination of settings creating a problem (a true software issue).
Did you use/test the new device before configuring it or restoring from backup?