My eldest son barley talks when he's home

My son who is 17 will only stay in his room playing games on his phone or his oculus and he barley comes out to socialize with his 3 siblings that live with me.

And I can't ever get him to talk about himself and at therapy he can't even name on positive thing about him his answer was that he had a decent about of friends.

He won't even talk about what he's into his sexuality, interests, or his days at school can anyone tell me what may be wrong with him?