It does appear as though the book is phasing through the adjacent blocks. The issue is only happening on one of the lecterns consistently. However, the solid blocks are 2 deep on every side of the lectern, I'm not sure why that would be possible. I have provided a link to the exported world.
I'm having the same issue playing on Bedrock. My lectern is in the Nether, not sure if that makes a difference. Exact same behavior as Alicia reported.
It does appear as though the book is phasing through the adjacent blocks. The issue is only happening on one of the lecterns consistently. However, the solid blocks are 2 deep on every side of the lectern, I'm not sure why that would be possible. I have provided a link to the exported world.
https://drive.google.com/file/d/1QX3C9lSw1eUJgkbO-A61RiPsSHDkFVjP/view?usp=sharing