Synchronizing favorites

I have Safari set to synchronize (via iCloud) my Bookmark favorites across three Macs (all running 10.10.3) and an iPhone 5s and an iPad Mini Retina. Since the arrival of the 10.10.3 update, I have started seeing multiple duplicates in bookmarks - sometime four or five copies of the same link. I have turned on iCloud Photos and have managed to synchronize a large photos library, and I wonder if that has something to do with what has happened. I have cleaned up some of the duplicates, but they seem to reappear the next day.

Is anyone seeing this issue? It is _really_ irritating.

David