Trapdoors close when flipping a page on a lectern

Trapdoors placed next to, directly above, *directly below or 1 block below a lectern close and open when flipping a page of a book and quill on the lectern.

Steps to reproduce:
1. Place a lectern
2. Put a book and quill on the lectern
3. Place trapdoors adjacent to the lectern

*If a trapdoor is placed directly below the lectern, no other trapdoors on the same level will flicker. But if a block is placed directly below the lectern all trapdoors adjacent to that block will flicker, including directly below that block.

All the trapdoors in the included pictures open and close when flipping the pages of the book. The direction of the trapdoors seems to not matter. This bug can be reproduced with all the kinds of trapdoors, including iron ones.