In multiplayer, if a client player picks up items from the ground via quick loot, the ground piles do not get updated at the host and at the other clients. Therefore this bug causes one item to be picked up by multiple characters, and can be ultimately used to duplicate items.
Steps to reproduce: 1. Start a multiplayer game with 1 host and 1 client 2. Drop two items to the ground as the host 3. Open quick loot on both the host and the client 4. Pick up one of the items via quick loot on the client 5. Notice that the host's piles did not get updated; pick up the same item as the host; now you have a duplicate