Got through all of the quests, made it to the last urn that is supposed to start the boss fight and when I pick it up nothing happens. The single target quest maker on the mini map changes into a yellow AOE quest maker and the objective says "TAKE THE VESSEL" but I already did. I've tried changing warframes and from solo to public and back. Nothing seems to work. After 3 days doing these quests it really sucks to get stuck on the last part.