Heads not working with player skins

v4.1.0

Spigot 1.11.2

I attempted to put a players custom textured head on a mob. The head never seems to update the skin on it and remains the default regardless of what I put into the options for the item.

I equip my mythicmob with the following head:

COS-SkeletonSandHead:
Id: 397
Data: 3
Options:
Name: SkeletonMan

I even tried the URL option with no luck

COS-SkeletonSandHead:
Id: 397
Data: 3
Options:
SkinTexture:...

Heads not working with player skins