Make sure in his cage he does have lots of chew things, some hammies don’t like them (like mine), but they’re always bound to love the dog treat called Whimzees which is great for keeping their teeth down.
All I can think of is that the taming process at the start was a little stressful/rushed for him and now he associates your hand with danger. How does he act when you’re around the cage? I’d say leave putting your hand around him while he’s awake and just sit next to his cage speaking to him softly for a couple minutes for a few nights. If he seems completely comfortable in his own cage with you around, take him out into the bath, scatter treats around so he can have fun finding them but don’t touch him, let him just get used to your scent and sound in there. Then after some nights in the bath, offer him a treat in your fingers.
Don’t give up, any hamster can be tamed to an extent. Hamsters bite when they are frightened and I’m sure he isn’t biting for no reason. Take it slow and I’m sure he’ll get gradually more and more used to you
