I have created a few multiblocks in Patchouli, and some of the Create entities (specifically shafts and hand cranks, in this instance) do not render in the Patchouli book. They are invisible.

If I disable Flywheel, the entities do render in the Patchouli book.

I am using Flywheel-1.16-0.2.4, but this was also happening in previous versions of Flywheel.