Trying to make a custom mob for a "boss fight" in a map, but every time I try to summon it and have a player skull equipped, the Steve head is the only texture I see. Same thing happens when I give the skull to myself in creative. When placed, it takes on the correct texture, but when worn you get the Steve head.

What I expected to happen was...:
Spawn a skeleton wearing a ghast player skull (SkullOwner:MHF_Ghast)

What actually happened was...:
Skeleton spawned looking like Steve

Steps to Reproduce:
1. /give @p skull 1 3

2. Place skull on ground/wall, not how correct texture is applied*
*Might be a client-side bug for me, but it takes a second to render the correct texture when placing
3. Wear skull as a helmet, and note that you now have the Steve head

In context:
/summon Skeleton ~ ~1 ~ {Equipment:[{},{},{},{},{id:minecraft:skull,Damage:3,tag:{SkullOwner:MHF_Ghast}}]}

I have confirmed that the SkullOwner tag is valid by adding a Count:1 between Damage:3 and tag and adding DropChances:[0f,0f,0f,0f,1.0f]. When skeleton drops headgear, it is labelled as "MHF_Ghast's Head", and will place on surfaces, displaying the correct skin.