i was building a home

I was trying to move one of the new bookshelf to another location and when I placed the bookshelf with the NBT tag there, the books were there, but they were invisible in the bookshelf

how to do it:
1. take one of the new bookshelfs and some random books 
2. but down the bookshelf and put the books there 
3. copy the block with the NBT tag 

when you place it down the books are but also aren't there