Just a thought fmb--stopping drinking and recovery are not the same thing.
He may be dry, but it doesn't sound like he has dealt with underlying issues that led to drinking
in the first place. Without that, denial becomes a new and terrible "coping mechanism"
Maybe that's part of the mystery--recovery looks like recovery,
but what he's done is run and hide, surrounding himself with distractions.
It won't work in the long run.
I hope things work out with your son--sending you both the best