Loot Box Problem

No another player isnt even looting it and I press square to loot and drop items. So let's so I'm running a hemlock and I have heavy with no space left in my backpack. I kill someone I go loot their body myself nobody with me and i switch the hemlock for r-301 and now i have to exchnage my heavy ammo in the death box but when i go to drop my ammo to make space it glitches to where I cant see how much I'm dropping I cant drop more than one thing at a time only outside of a death box I can drop more than one thing and see what I'm dropping.