This issue does not happen in 1.13.2, but it does happen in the latest 1.14 pre-releases.

Go to craft a book with 1 leather and 3 paper and the shapeless recipe works fine.
Now try to craft a book with the 'classic' shaped recipe, with paper in the lower right corner, and leather on 3 sides. It will seem to do nothing, but if you add more paper, (at least 3) it will craft the book, and take 3 leather, and 1 paper. It is tough to explain, so I attached some screenshots.