On PC and even console, I have seen that when mobs come to an edge of a platform or even randomly, the mob would spin aggressively in circles. This seems to happen on every version of newer Minecraft and although not being a major bug, I feel like it's pretty annoying seeing a lot of mobs just randomly spinning. Here is a clip on youtube I have found which shows what happens: https://www.youtube.com/watch?v=DN4O1fvREko