I spawned endermen on scaffolding THAT WAS ABOVE AIR and went into survival but when i attacked them, they weren't moving even though their mouths were open, and when i pushed them off of the scaffolding, they started moving again and killed me.

What I expected to happen was...
I thought they would scream and start attacking me like always.

What actually happened was...
They stared at me with their mouths open but didn't move.

Steps to Reproduce:
1. Create a platform of scaffolding
2. Spawn endermen onto the scaffolding
3. Get into survival/adventure and anger the endermen in any way.