It’s normal.
Exercise, is puppy getting enough?
Sleep, are you enforcing naps? Puppies are like toddlers, they get over stimulated easily, they need sleep and you need to put the routines in place for this to happen.
Playing, are you playing with him before he starts the behaviour demanding play?
When puppy bites, first move away. That needs to be the immediate reaction. Then offer something else. A chew toy, a tug toy, take outside for a run around, etc. Don’t make this redirection a reward for the biting, that’s why you move first.
If all of this doesn’t work, enforce a time out for biting. Put puppy in another room, wait for them to calm right down before you let them back in.
But also, this is what puppies are: really really hard work! Are you working with a trainer, do you really have the time, energy and emotional capacity to put in to this puppy? Puppies need training constantly for months and months. If the answer is no, this is the time to tell the breeder you have made a mistake, the longer you leave it the worse for everyone.