Appears to Add Books But Doesn't

For the past week I have been trying to add books to my list, but when I put in the IBSN it says added just like it used to, but I cannot find the book that was added, regardless of how I sort. I tried this with a newish NYT bestseller and got the same result as one of my old weird books.

Any ideas what could be causing this and are others experiencing the same thing?

Post some of the isbns and I will see I can fix the problem.