"Complete the current Seasonal activity or Exotic quest on the highest difficulty." I have run The Coil (not to its max length of that exists), The Whisper Legend, Zero Hour Legend, and Seraph Shield Legend when it was in rotation and this still has not been completed. This is my only task for Guardian Rank 10 and it would really suck if this bug stops me for Season 23. If anybody knows the EXACT activity for the current season or a solution to this, PLEASE let me know.