Xbox one X - Dayz 1.18.154955.
Basically you or anyone else bugs, usually one of your arms disappears, the other players see something in your hand, a knife for example (which in reality does not correspond to what is actually in your hand, in the case of the video below it was a M4), you can't see the gun, you can't hear the gunshots, just the sound of the shots when they hit close to you.
In this other case, one of the arms didn't disappear (it's another player, not the guy in the video above), but the same thing is repeated, he had a MOSIN in his hands, invisible and inaudible, you can only hear the recharge sound and shots hitting the wall.
Undoubtedly, update 1.18 broke the game on several levels: inventory, performance (more than it already was), recurring crashes and that... a massive desync problem between players.