Sometimes all of those hormones that are still raging through their system can reach a peak after neutering. He should calm down.
Also, nipping is a very common young bunny behavior that might not be related to hormones at all. Teenage bunnies are still teenage bunnies. Does he nip when you’re sitting down and playing with him? Or does he do it as a way to control you (get you to put him down, move out of his way, etc?)
If he does it while you’re playing, I would just tell him no or make a high pitched sound, then get up and leave while turning your back on him. If he’s just playing, he’ll learn that playing with his teeth is not ok.
If he’s trying to control you, you need to do the opposite of what he wants. If he wants you to move our of his way, say no, do the high pitched yelp, or whatever works for him, but don’t give in or he’ll keep doing it.
I hope this helps! He’ll calm down with age and as his hormones dissipate.