The Zombified Piglins got a new texture on the Nether Update. It went from the old Zombie Pigman texture to the new piglin related skin. After 1.16.40 the old Zombie Pigman skin texture came back and overwriting the new texture.

Steps to Reproduce:
1. Spawn a Zombified Piglin with a spawn egg, the /summon command or find one on the Nether

Observed Results:
The Zombified Piglin has an old Zombie Pigman texture from before the Nether Update.

Expected Results:
The Zombified Piglin was supposed to have the new Piglin related skin from the Nether Update.