I can't get him to progress the quest to where I have to get the medical supplies. I had to spawn Isaac because he dissapeared (with player.placeatme) I got him the 100 scrap needed and went back to Contreras and he only offers 2 basic dialogue options.. the "buy" one and the "leave" one. Any idea how to get this unstuck?

Try buying something, then see if there is an option, I had a similar bug

no dice any other thoughts?

Are you doing the quest to expand his inventory or get This Machine?

The gun and to expand inventory..