Scott's companion quest failed?

[Mograx]

I got the quest he went missing. Met the mutants, tried to climb the wall but said it wasn't the time, google said to finish escorting the mutants, so I went to the mutant city, dealt with Cain, then went to the rover to look for him immediately. At the rover, he was there, the quest failed, and I can't seem to further progress his story.
Why did I fail this? Bug? I'd like to know if there was a very utterly tiny specific circumstance I missed in case I want to replay the game, but knowing this quest failed makes me want a refund lol. What abysmal quest design, I HATE not finishing every companion quest.

[Drawar]

You have to finish escorting the mutants until they leave you, but don't leave the map at this moment, you can then go find Scott.