Creator email search in library only returned most recent submission, other searches also not returning results.

I'm pretty sure I have four bookbuilder lessons currently in the shared Library (ID 2353, ID 2568, ID1670 and ID 2800). I needed to double check which of my books were in the shared library for a highlight story. I ran a library search using creator email, and only one lesson returned in the results. But when I went back and got specific lesson id numbers and entered those into the library search, all the lessons came up. When I searched using just the lesson type (bookbuilder), only 2 of the four lessons returned in the search results. Yarks. I am confused. Help!