so, ive noticed this issue with pneumaticraft drones getting stuck in stone pillars, i reported the issue to their tracker, they redirected me here and asked me to mention this:
If your blocks don't have a full block shape (specifically, if Block.isOpaque(shape) returns true for your block's collision shape), but the block has an entity-blocking collision box, then entities will get very confused when trying to pathfind around your blocks - they think they can path through, but just get stuck forever.

Solution is to make sure that Block#allowsMovement() is properly overridden for any such blocks. A simple implementation would just be to return false for any block which has a non-empty collision box.
hope this helps in improving the mod :)

I hope it's fixed

Umm...., sure