When I originally did shadowkeep's intro mission, I had my quest and bounties full and couldn't receive the ?????? quest step. It was then possible to accept it but it wouldn't complete visiting eris morn because the quest had already gone past that phase. It never went away till Beyond Light. Now it stays on the quest terminal. I can accept it, but it dissapears from my quest and bounties tab when I exit the tower, only to return to the quest terminal.