I thought you had to be 45 to access Argus. Is it this character or another?
What was the last quest you completed on that quest chain? Did you go to the Exodar, board the Vindicaar, and travel to Argus, then port down to Krokuun?
Edit to add: I see. Anyone can be summoned to the dungeon or by a warlock, but you can’t start questing until after officially entering (happened to me).