I've never done skolas cause I could never find a group on ps3, but recently started trying again. I had kept my last treasure key safe in my vault for like a year, but moved it to my titan the other day since I realized the app cannot move treasure keys. Then I decided to open sterling treasures, but after I opened the first one the treasure key swapped places with it under my cursor and I deleted my only treasure key!!! This was the only time I have ever audibly shouted NO!? At a video game before! Thankfully, I went to year one poe right after, spawned in right before the final round, and a treasure key dropped from the two chests in the treasure room within like 20 minutes! Thank God, I was so releaved. I've done hours of year 1 poe without treasure keys dropping.