Mobs unable to pathfind properly when scared or idled on transparent blocks

The bug

When a villager is standing on a transparent block (such as leaves or glass), and its scared from a hostile mob, it will either move in short quick bursts or not move at all. If there is a solid block at all, it will just run to it and stay there (even if it is close to the hostile mob).

Video demonstrating the issue: https://youtu.be/4t75cJ3NBHI