Is "Shroud walker" supposed to allow mobs to subvert immobilization ailments?

Descriptions from in-game skill gems

Elemental Ailments Freeze and Electrocute:
Electrocution: Electrocution is an Ailment that interrupts the target's actions and prevents them from performing any action.
Freeze: Freeze is an ailment that causes targets to be unable to move or act.

Immobilised: A target is immobilised if it cannot move, for example due to being Frozen, Pinned, Heavy stunned, or Electrocuted.


Regularly, mobs imbued with "shroud walker" are able to teleport and move while they are frozen and/or electrocuted. Is this supposed to happen or is this a bug? If it's not a bug, why can these mobs move while immobilised? I've also seen other mobs continue to have their abilities or actions trigger while they are Frozen or Electrocuted. This doesn't seem like its should be happening.