PC My NPC's don't have hats

[Admiral Voidzuli']

So, my npc's in my world never wear a hat when a party happens. It may be some of my resource pack from the workshop causing it, but i just wanna know what's causing it.

(Ignore the creeper demolitionist)

 

[Blue_M4ge🌳]

The resource pack that changes the demolitionist to a creeper does this, not entirely sure why.