iOS / iPad fails to sync with Big Sur
When I plug my iPad or iPhone in it appears in finder on the left but when you click on it you get a blank window on the right.
When this happens if you open Activity Monitor I find "com.apple.amp.deviceui" is taking around 99% to 97% CPU and the Recent Hangs count keeps going up as I watch. Eventually (1 hour later??) this stops and I get the Normal sync menu on the right and "com.apple.amp.deviceui" drops to around the 10% CPU with the hang count stopping around 70ish.
The message at the bottom of the Sync menu says "Syncing (Step 5 or 6) - Reading Photos library", if I leave it like this it will stay here for days (assuming I don't unplug my iPad / iPhone.
I can then change the settings in the sync menu but this then greys out the "Skip Photos" and "Apply" buttons. If I don't change any settings and click a button the sync menu in finder hangs.
In an attempt to fix this I have:
- Restarted both my Mac and iPad / iPhone
- Rebuilt my photo library
- Removed excess files from the internal SSD to free up space
- Reinstalled MacOS BigSur
- Done a full Apple diagnostic (formally hardware test), Passed
- Ran First aid on "Macintosh HD" and "Macintosh HD - Data" in the disk utility tool, Passed
Has anyone got any further ideas what could be going on?
I'm afraid I can't upgrade to a later OS as my Mac can't go past BigSur
I also can't sync via iCloud as my photo library is to big to store in iCloud
iPhone 12 mini