Doing the story: took the portal to Duress: Heitor => Got stuck on load screen => Restarted the game => Tried to get back into the story => InstanceCreate failed. Error=1306; Product=9; Module=18; Line=624
I can confirm.
I ran alone all 8 rooms. Only an elite enemy spawned in the last room.
I cleared the last room, killing the elite.
No credit for the achievement.
Same boat.
Happened to me 30 minutes ago. Succeeded the event and no Luxon Tools.
UPDATE: Ran a 2nd time with only 4 other people and i got the item! 🙂