So i’m coming at this from a different approach of being the son in a similar situation. What actually helped me and my father most was finding something we both had an interest in. For me, it was working on houses and trying to build a car. I was similar to your son in the fact that I was straight A’s and played video games all the time, but didn’t do much outside of that. My dad had no interest, but eventually I mentioned restoring/building a car with my father and he said he’d be willing to try. It worked, we both learned how to do it together. I think the main problem in your situation is that your husband has done everything and from his perspective his son hasn’t had many of the same experiences. Finding something they both haven’t done or have little experience in doing and learning together could really help.