I Need Help With "the Envoy Part 2" Quest

I played this Quest up to the point where the questbook says "Retrieve the key to the base" where Maxie should spawn and open the door.
When i try to open it myself it says i need to use the catapult and interact with the grandmaster. But since i did that already and nothing happened, i think the quest is broken or something.

Is it possible to just reset the Quest or do i have other options to do it? I don't really mind doing it all over again but since it'll unlock a dungeon i really wanna finish it.

 

You have done the Avos temple and have the key in your inventory?

 

Yes i did that. I'm after the part with the Vault where i need to follow the trails on the ground through a Cave.

 

Ok. So you went through the tunnel and are now at the house?

 

Yes and no Maxie is there.

 

well, in that case I'm out of ideas. I would just make a bug report here