What the hell is going on in multiplayer? (Doom (2016))

In general, if we close our eyes to the game of some comrades who seem to be playing with input (they see through walls), and I understand when the bonus of the hunter and the scout is given, but they constantly stand around the corner and wait for the moment. I would understand if this there was a cop, in which steps are heard, and in the game the dynamics is fast + external noises. Next, some kind of garbage happens with skins, my skin turns out to be with another player ... wtf ??? I understand he could repeat it for a joke, but Not in 10 seconds! What is this? A game bug? Or does the game have no protection against cheaters?