Are there any files listed as part of the "All Sync Errors collection"?
If not could you try to remove the sync.lrdata file and restart LrD. This would restart/refresh the sync (metadata only).
Removing the Sync.lrdata might fix whatever the issue is. Or, at least, might trigger it to occur again.
You can find the sync.lrdata file here:
On Mac it's at /Users/<user>/Library/Caches/Adobe/Lightroom/Sync Data/Sync.lrdata
On Win it would be at C:\Users\<user>\AppData\Local\Adobe\Lightroom\Caches\Sync Data\Sync.lrdata
Let me know if it's now working.
I don't have a collection called "All sync errors"
and deleting the sync.lrdata file did not fix the issue. I restarted Lightroom and it went through the sync process very quickly but still did not add the missing images.
Any other ideas?
I have the same problem & worse. None of my LR 5.4 changes are syncing including full collection additions & deletions. Is this a known issue with ios 8.0.3 on the ipad/iphones?. The Sync.lrdata deletion did not work.
On my iPhone I created a new collection in the app and manually added the photos to it that were missing from my Lightroom Catalog.
I then opened Lightroom on my Mac and whilst it created the new collection that I had created on my phone, it did NOT sync any photos to it at all!
This would appear to indicate that the issue is something specific to those particular images since all other images seem to sync fine. There's nothing clearly different about them though.... they are just iPhone photos.