Interesting. Without master loot the chests were bugged in Normal though. But I assume after you finish the encounter, it's too late to exit and switch the loot. Hopefully it will just fix with the patch tonight.
Normal mode has that loot bag crap. Hard mode allows you to set up master loot. Our first chest was bugged on master loot for the second boss. Switched to FFA and we could loot the 4th boss no problem. Unfortunately we could not go back and get the previous chest. Hopefully the helpful protocol droid in a can will help us with it.