I had a grade 4 tongue tie that wasn’t diagnosed until I was in my 50’s. I had to do something called myofunctional therapy to teach my tongue how to work. During my second IJV decompression surgery, Dr. Nakaji had to resect the digastric and myo and hyo styloid muscles which initially left me with some deficits. I used the exercise I learned from the myofunctional therapist and now everything is working fine. I think a speech therapist could also help teach your husband how to strengthen those muscles.