Umm you know its bugged in a good way right? lol Its bugged in a way that you complete it faster. Since the progress is stuck at 100% the chest is always up. 5min and you get your weekly loot. take advantage before they fix it
If it stuck at 100% that just means the chest has spawned. You kill mobs by the chest till you get 3 Epic Keyes. Took me about 2-5min no joke. Then you use the keys to open the chest. You can loot it once a week
So get on all ur toons get in and get out. Collect your free loot before Blizz fixes it and turns it into a 30min per toon event like the others