If you could try killing a zombie with an item on it go to the item in the zombies inventory hold x (I think that's PlayStations equivalent to xboxs a button sorry I'm an Xbox player) make sure there's nothing in your hands and switch from the zombies inventory to your hands and release x, and that should allow you to drag the item to your hands. (By hands I mean the inventory space located below your character when you open up your character screen, not your glove slot, just some clarification. Hope this helped.