There's a loot diving bug - not sure if it's a known issue.
When a loot object spawns at a level edge ( I believe ) there's a strong chance that it can cause you to freeze up and wait about 20 seconds with items disabled and still not grant you a chance to grab the loot object at the end. Pretty frustrating, and has been occurring since the introduction of loot in the first place. Maybe fixable by forcing loot to not spawn at level edges?