I played and finished the lost in the light quest, but I don't have the prismatic healing grenade on my warlock. Is there any way for me to replay the mission and get that chest? I'm not sure if I skipped past it or the server issues just didn't give it to me. I looked up the acquisition method on youtube and tried visiting the same location just now, but the chest isn't there. Is Bungie able to help me get this ability back, or can someone direct me how to acquire it after I've already completed the Ergo Sum questline?