Hi. I thought I had got on top of syncing bewteen Lightroom classic and Mobile. I set up some collections in Classic of Photos I wanted to review on my ipad. They synced fine. I reviewed them on my ipad and made some changes (I marked them and rated them). The sync from Ipad to Creative cloud has happened, however when I go into Lightroom classic, none of my collections are showing as syncing (The little button has disappeared).
Thanks Johan. I did, it wasnt paused. I found that it was being caused by an error on Sync. Apparently I had two photos with the same filename. No idea how that arose, but fortunately I didnt need either, so just deleted. Switched sync to pause then restarted and everything went back to how it should have been.