Mobs get stuck in the ladders, when you compare them in the stairs and when they walk at the stairs, they stop walking, they stand in one place. They also do not see you and sometimes do not attack. (It was in earlier versions) This happens when the Mob approaches the ladders, if the mob is in the block of the ladders itself, does not see the player and stands still, as it is stuck in it as in a regular block. Nothing to add here, I showed everything in the video. This world is new, I didn't do anything except what was shown on the video.