Good news.
I have been reading and posting here since the thread started. Ignored most of the post in the last 6 months as many people claimed there was a fix, while others simply didn’t understand the problem or was talking about something else like cloud sync issues instead. I just kept ignoring all the thread notifications.
Saw Nogee43’s reply above, and it has motivate me to confirm the following. With the latest iOS update (13.6) and OSX (10.15.6):
- Albums no longer need to be in root level [that was fixed a while ago],
- No more duplicate photos being synced (usually one with all the metadata, and one with missing metadata like geo-tags, etc.) [this was also fixed sometime go],
- The problems where incremental album syncs (I.e. selecting an additional album to sync) would render whatever was previously synced at the iDevice being messed up (e.g. missing or duplicate photos) is no longer a problem. This fix happened with the recent software updates. This means, you no longer have to unsync everything before doing an incremental album sync,
However, and I believe this aims directly at Nogee43’s observations:
- It seems you will still encounter incomplete syncs on your idevice, showing “syncing” at the bottom of incomplete albums, when ANY album happens to contain a photo where you have selected a face to be the KEY PHOTO under the PEOPLE you favorited in your Mac Photo Library. You have to reset the faces on your Mac and let Photos rebuild the faces before you name the faces again, but you can NEVER pick your own KEY PHOTO (unless it is from an album you won’t be syncing).
- Which means, the fix is to create an “dummy” album you will never sync to your device, which contain photos you intend to use as key photos for the faces you have identified. Of course, you don’t even need to do this step if you don’t ever pick your own key photos. (Just to be safe, I made sure the photos in this dummy album aren’t links to the same photo from another album you will sync. I actually created a duplicate of photos I wish to use as key photos using screen capture and importing them into the library)
With the above, all my sync problems have now gone away.
There might be other things I’ve done in the past that could have rendered my success unique and non-replicable (such has having repaired and manually rebuilt the whole Photo library on my Mac from scratch a few updates ago), but I doubt it. Nogee43, please try and see if you have selected any key photos for people you have identified, and these photos are also in the incomplete albums you’re trying to sync.
Which brings me to (if the above is proven correct) the last problem of incomplete syncs should be an iOS problem, specifically with the key photos under People potentially conflicting between those from OSX and iOS.
Apple (or God), if you’re reading this, please look into it.