I don't know if its Chat Heads or Beautified Chat [Client] but when I have both installed, the player head is missing, but there is an empty space where the head should be.

I've tested this with both 1.19.2 and 1.20.1.

For reference, this is the mod:
Beautified Chat [Client]

First guess:
This line might skip the head rendering.
Gonna need to check and potentially write a PR.

Yep.

Fixed it for 1.19.2 at least. Gonna do the other 3 supported versions of Collective and then PR it.

The PR has been accepted, Collective 7.8 shouldn't have this issue anymore.