Could you please make sure that the Picture saying "Partially Synced from TJ's iMac" is not missing from the Lightroom cataog.
A missing picture would show a " ! " sign on top right of image thumbnail.
Found the problem - never mind.
Thanks - T.J.
What was the problem, as I have the same issue
Please make sure the Picture you are trying to sync is not missing in Lightroom catalog .
Locate missing Pictures .Refer https://helpx.adobe.com/lightroom/help/locate-missing-photos.html