Ironband's compound warrior quest problem?

[Dizzy]

So I'm doing this quest which requires me to loot a chest that spawns next to a mob. I've killed the mob twice now and the chest still hasn't spawned again (someone looted just before I got there). Not sure what's going on here. Hopefully I can get some insight on this.

[rumers]

The chest is there just the spawn time is like 5+ mins.I did the quest with my warrior.

[Dizzy]

I eventually got it. The spawn was more like 20 mins. The main mob that spawns next to it had like a 5 min spawn time and I killed him 3 times before the chest finally spawned.