When I try to write in a book with the off hand it doesn't keep what I wrote in it.

Bug summary:
When I try to write in a book with the off hand it doesn't keep what I wrote in it.
What I expected to happen was...:
When I write in a book opened in my offhand then it should save what I wrote.

What actually happened was...:
when I opened the book in my left hand and wrote something in it it didn't save what I wrote.

Steps to Reproduce:
1. press f with writable book in hand,
2. Right click the book to open it,
3. Press the done button at the bottom of the screen
4. Press f again.