Apple Books problem in High Sierra

suddenly my Apple Books is not updating to show my latest additions. I have a ton of books in the program and it has always synched well across all my devices. Suddenly it showed all my books up to May, but none of the additions in late May and June so far. I signed out and back in several times but nothing changed. I then clicked on Check for available downloads and it came back having removed the May entries.

I went to check my iCloud info and found 2 different listings for iBooks - one significantly smaller than the other. I’m afraid to delete either of those because it warns me all the books in it will be deleted on all my devices. Too much invested to do that lol.

Would appreciate any guidance you folks might have!