Weird things happen when you break the decorative chests; they display the chest texture map instead of a block breaking overlay.

Bookshelf version: 1.4.2.331
Mod version: 1.1.5.93
Forge version: 12.18.2.2117

Examples:

Very interesting, thank you for reporting. Will fix soon :)

This is actually an issue with the Bookshelf code. I have opened a copy of this issue over there. I have already solved the issue, just want it on the right project so it can be tracked in the future.