I went to complete the mission for the final stasis fragment. After destroying all the small pyramids with the exotic stasis grenade launcher, the large pyramid and enemies didn't spawn in. I went to orbit, loaded back in to Europa, and the mission was gone on the map. I abandoned the quest, went to require the mission from the lady in southern europa, and it said it was already obtained. Basically, the final stasis mission has bugged out so I can't complete all my aspects. Weird. Sad, because I want to be able to harvest the stasis shards in pve.