Had a similar issue. Picked up a pistol mag with the F hotkey, it went straight into the empty pistol and bugged it out so I could no longer interact with the magazine. No reload, no firing etc. Died soon after. Can't remember the name of the pistol, IJ-70 I think. I do remember it had one bullet in the chamber and the magazine must have had 1 as well because it showed two bullets in the inventory.