I just wanted to do the Quest "Born in Darkness". In the first quest step you have to collect 50 energized ether. This worked for me. But the second thing was to get stasis melee final blows. I had 0/10. I equipped the new Subclass and melee'd many mobs, all categories. Tried with melee skill and super main skill and explosion. Nothing of this gave me progress on the stasis melee kills.
Then I thought "Ok, lets abandon the quest and try again"... I abandoned and.... I don't get the quest again from the Exo Stranger..