Polar bears cannot jump up one block from snow layer to snow layer when hostile and facing north or west

The Bug

The polar bears can't jump onto snowy grass blocks or snow blocks from snowy grass blocks or snow blocks.

Steps to Reproduce:

1. Creat a 5*5 grass block or snow block platform and cover them with snow layer.
2. Surround the snowy platform with grass blocks or snow blocks and cover them with snow layer.
3. Summon a polar bear in the center of the snowy platform.
4. Set your gamemode to survival or adventure.
5. Punch the polar bear and run away from it.
   -> The polar bear try to chase you but it can't jump out of the snowy platform.