From what I understand, it's pretty common for guys (I can't speak for women because I haven't been in a relationship since I got sober). I think it's a combination of all the brain chemical changes that go along with sobriety, together with the fact that for a LOT of alcoholics, sober sex feels weird (like everything else does that we associate with drinking). He also might still be dealing with feelings of guilt about the past. So it isn't that unusual in early sobriety, but at 9 months sober it seems like there should be SOME improvement.
You sound very loving and patient, but you didn't sign on for a celibate marriage. Is he open to discussing it with a professional? A doctor or therapist?