I checked with your config, everything works fine. With your config, the player who first caused damage to the NPC can loot crates, other players cannot. Please note that if there are other players on the team, they also have the right to loot. Also pay attention to whether you dealt damage to NPCs, because damage does not go through from a long distance. I didn’t find any errors, it’s also likely that other plugins are influencing it, check on a clean server if possible. Let me know the results please