Syncing problems since 15.2

When I create a new collection in Lightroom Classic 15.2 in order to sync photos from my Mac to other devices (iPad + iPhone), sometimes none of the photos will sync, sometimes a couple only will. What is strange is that if I stay in the Collection folder and make a virtual copy of an “unsyncable” photo and make edits to it, that virtual copy will get synced, but the original photo will remain unsynced. 

When I look at “diagnostic” in the Synch section of the settings, all it will say under “Error/Synch details” is “Image”, which is not helpful at all. I’ve tried rebuilding the sync data more than once, but it didn’t work. 

I never used to have sync problems before 15.2, so I hope this can be fixed. Thanks!