Thanks but that doesn't work. Ive done all of that already, a multitude of times.

No you haven’t. Your triumphs & your quest say you haven’t done it.

Gee, I think its because the quest is glitched. Sorry to be rude but that's the main point of what I'm saying. Ive opened all 3 of the chests, both with and without assistance. Ive also played it on expert several times to both completion and until I quit. It literally just isn't popping up, nothing is.

Post a video then of you doing that specific area & opening the chest

Ill do it tomorrow. My team started the boss encounter too early and I'm honestly tired of d2. Although I have one minor question. What does the third chest have to do with the first Catalyst? Considering that chest is for a completely different catalyst quest of which I DO NOT have.