It’s tough. But this needs to be attempted /fixed by his father. Evidently there’s more to this and a back story. I might not understand but if there are visitation rights then use them regardless if the kid wants to go or not…
One way to break into this. You might not like this but meet the son where he is at now. Have your husband find out what games he’s playing and ask to teach him how to play. Like on a TV console or computer. My kid also played games all the time and even in college (graduated almost two years ago in engineering and still playing games)… Getting to level 13,245,679🤣… Is pretty hard to do and I will give you articles telling you it’s a good thing to let the kid do even especially if thinking about engineering… Lol.
But the kid is hiding. To me it was going into my room and playing loud music to drown out the yelling. Trust me, I have been there. He’s just hiding behind the game and his mother let’s him. You can’t change his behavior and your attempts will only alienate you/your family from him. Meet him where he is at today. Slowly integrate your household rules but yes, in your house he needs to integrate.
But more importantly the father needs alone time with him for many, many reasons. Once that is on its way to repair the rest will fall in line.
Any reason your husband can’t take him away for the weekend? Looking at colleges or just because. Maybe there is a ballgame they can drive a short distance to go to? Just being together is more important then the words spoken. The words will come.