During every sync from my MacBook Pro 2019 to my iPhone 11 Pro Max and iPad mini 5, all 3300 photos are removed from the iOS devices and then reinstalled during the same sync. This happens whenever there’s been even a slight change in the MacBook's Photos app – for example, a new photo added or a deleted photo or an edited photo. Even one change triggers this problem. If there have been NO changes at all, the sync works normally.
The problem began with iOS 13 and Catalina. In the past (using iTunes and Mojave and iOS 12) only the new or changed photos were synced, leaving the other photos as-is. That’s the way it’s supposed to work. But now each sync takes a long time because of the removal and reinstallation of all photos. I really dread syncing now.
I do not use iCloud and I’ve never used iCloud. I sync with a cable connecting my devices to my MacBook.
MacBook: 10.15 with Supplemental Update
iPhone 11 Pro Max: iOS 13.1.3
iPad mini 5: iPadOS 13.1.3
Things I've tried but haven’t solved the problem:
- Restored the iOS devices
- Deleted iPod Photo Cache on MacBook several times
- Turned off “Sync All Photos” and then re-enabled
- Removed all photos from iOS devices to re-sync cleanly
- Always updated all devices to the most recent macOS and iOS
- Used “Option” when opening Photos on MacBook to make sure there’s only one Library
- Used “Command – Option” several times to “Repair” photos on MacBook (never found a problem and this completes quickly, maybe two or three minutes)
The Apple senior techs have not been able to solve this. I’m hoping someone here in Apple Discussions can help me.