Put the summary of the bug you're having here

What I expected to happen was...:They face a direction I've set.
Describe what you thought should happen here

What actually happened was...:

When I turn off the game and re-open the world, a shulker always faces north and a wither always faces west!**

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