We believe this bug happens while slowing blood loss (for me, that key is “w”) and being revived at the same time. After being revived, I could no longer switch weapons, throw the knife, switch to weapons or meds or grenades. I could, however, still access my inventory and drop everything for my duo partner. Whoever this bug affected, basically became bait for the rest of the game.
I have hours and hours of this last wave’s footage, and it’s happened to me and my buddy at least twice that I can remember. I can find it if you want, but it’s just us complaining