Books app “Documents and Data” taking up over 10 go of data?

I’ve disabled all syncing to any cloud storage and deleted all books both from

the app and my iPhone, Books still shows over 10 gb of data under storage in settings. I’ve come across a bunch of posts about this problem with no solution. Here is my solution:

1. Deleted the Books app. Immediately freed up over 10 gb of storage space. Before I did this I made sure I had copies of the books I wanted to keep in a directory in my phone.
2. I installed Google Books. Shared the copies of books I had kept to the app. Nearly identical app with the exact same books I had using the Books app. The storage used under “Documents and Data” is now 77 mb.
3. NEVER buy an apple product again, such garbage.

Hope this helps!