Mobs will try to walk and pathfind over buttons, but stop and start jumping as if they are trying to jump over the button. The mobs will not stop untill hit/pulled away from the button. After some testing, I can confidently say that I have seen it happen mostly with Horses in confined spaces (As seen in screenshots) and pretty much all mobs that can move on there own. This is a very annoying bug that should really be fixed.
I have also observed that almost all other mobs will often get stuck while pathfinding over and/or onto non-solid/non-full blocks such as trapdoors, slabs, lower-half slabs, and similar blocks. Something in the pathfinding AI for mobs is clearly broken. I have seen variations of this bug happen many times on Android, Windows 10, and Xbox.
How to reproduce:
1 - Summon a mob (such as a pig or zombie) in a closed off pathway made with blocks mentioned in the description of this report.
2 - The result is that the summoned mob will get stuck on the problematic block(s) and jump around.
The intended behavior should be that the summoned mob reaches the other end of the pathway (or other destination) without getting stuck on the problematic blocks.