Currently the Commander Cronkite Co-op map is kinda broken, even at tier 2 he has around 10k-ish health/shield and for you to get a chance at loot from the chest you need to deal damage to the boss. So the problem here is most people just shred the boss instantly and the people who never got a chance to do damage get no loot.. The only fixes I can think of are to up his health/shield or only let people open the door if you are all there so you get a chance to hit him.

And yeah I know that you can just communicate to your team that everyone needs to do some damage but there is always some *** that insta kills him and gimps everyone else out of loot.