Not able to open inventory, change weapon or use anything

Happened twice to me so far where I'll be doing an action and suddenly everything stops working apart from opening menu to quit. All I can do is run around and shoot if I have a gun already in my hands, or if it's a grenade it only lets me punch. I can't use the number keys to select weapons nor open inventory, and cannot interact with anything when this happens.

Happened to me as well, usually followed by a d/c 3 or 4 minutes later. I think the server dies a slow death.