I have experienced an issue where removing a book and quill from a lectern will sometimes cause the book to disappear.  My lectern is in the Nether.  I'm playing Bedrock edition on Realms.  I have experienced this in two different worlds.

Steps to reproduce:

1. Write in a book and quill (unsigned)
2. Place it on a lectern
3. Later, when needing to update the book, remove the book from the lectern

Expected results:
You should be able to remove the unsigned book without it disappearing, edit the text and then replace it for later editing.

Observed results:
The book simply vanishes from existence.  It looks like it bounces into another block, or just hovers for a second and disappears.  It doesn't happen every time you try to remove it, but probably 10-20% of the time.

I'm creating a nexus of sorts where I would like to document destinations in my nether tunnels.  I can't do this if my books keep disappearing!