The armor on a drowned doesn't line up with the model when it is chasing a player underwater. I've attached some pictures that show what I mean.
- Summon a drowned with armor:
- Make sure it is underwater, and go into survival mode to have it chase you. The helmet will be too far back on the drowned's head, and the movement of the drowned's arms and legs will not line up with the armor's arms and legs movement.