The bug
Mobs spin when they are on scaffolding. When the mob wants to change direction, he turns on himself.
How to reproduce
Spawn a mob on a scaffolding and look what the mob does.
Examples
Here are a few examples in videos:
Linked issues
is duplicated by 12
MC-279730
A bug similar to MC-279726
Resolved
MC-242503
Mobs above scaffolding on air doesn't move
Resolved
MC-225734
Endermen wont move when hit on scaffolding
Resolved
MC-201135
Mobs going crazy while pathfinding by scaffholding
Resolved
MC-158275
Enderman not moving on floating scaffolding
Resolved
relates to 2
Attachments
Comments 15
New findings from MC-158275: If the scaffolding is floating, mobs behave as if it was air. While standing on it, their (pathfinding) AI seems to not function (they're waiting to fall down). If there are blocks around the scaffolding, they'll walk along those, but won't walk onto the scaffolding blocks.
If there are blocks below the scaffolding however, mobs will enter it, as they believe that there are blocks one layer below that they can stand on. However, they don't fall down as they expect, but are standing on top of a block that they don't know how to pathfind from.
I attached a video showcasing the behaviour with floating scaffolding a bit:
Actually The Mobs Can't path find through or on scaffolding
They'll treat Scaffolding like a solid block in the same time they treat it like air when they have to walk on it