Maybe he needs a break from social immersion. It can be a bit like being thrown into the deep end of the pool and struggling to keep your head above water all day every day. It leaves you too stressed and exhausted to concentrate on academics or a social life outside school. Maybe if he has 6 months break just doing online school he can spend the next 18 months finding activities that he will enjoy and will meet his social needs into adulthood. Since most school activities finish at graduation this may leave him in a better situation socially.