Can't see skeletons in servers, but can see them in single player.

Put the summary of the bug you're having here

What I expected to happen was...:
I thought that I should see skeletons here.

What actually happened was...:
I didn't see any skeletons.

Steps to Reproduce:
1. Turned on a resource pack for 1.14.4 called "Creature Variety 1.7.6 +3D".
2. Took off "Creature Variety 1.7.6 +3D"
3. Boom! No skeletons.