Iron Golems hanging in mid air

Put the summary of the bug you're having here

What I expected to happen was...:
Iron Golems falling into a 5x5 lava pit that i built.

What actually happened was...

About 1 / 20 are hanging over the lava not falling in. See attached screenshot

Steps to Reproduce:

1. Put a step by step guide on how to trigger the bug here
2. ...
3. ...