Unsure if I missed a TWID note or something, but was able to complete the ROTN Spire of the Watcher solo flawless today on Eternity mode (which is supposed to be the near equivalent of Normal mode for the regular dungeon). Didn't disconnect, leave, or die the whole run - but I was not awarded the achievement for Solo Flawless. I'm guessing this is due to the event "version" counting as a different dungeon but considering the equivalent if not harder challenge on Eternity or Ultimatum, I'm surprised we can't get the solo flawless achievement this way while earning the new loot. Again, might've missed comms at some point about this but I don't remember seeing anything about Eternity or Ultimatum not counting for achievements - just Explorer (which tracks since it's designed for solo and easier)