Tried to loot a shotgun, it disappeared

[Kneeyul 0]

Date/Time: 5/23 , 10:45 PM EST

What happened: I tried to loot the fancy shotgun (M104 I think) into my backpack that I spawned with, and the shotgun disappeared. I had 5 slots open in the backpack, and I'm assuming that wasn't enough.

Where you were: At a warehouse that is west of Solnichniy, I believe

What you were doing: I tried to loot the shotgun into my backpack, and it just disappeared, probably due to not having enough room.