1. The breeder has nothing to do with how calm and docile your snake is.
2. Let him chill for a bit longer. He may still be stressed out from the move, and change in environment.
3. A mouse pinky is way too small.
4. There's no need to contact a vet.
5. What was the breeder feeding him?
Welcome to the forum!
p.s. Post a pic if you have one.
X2
Also just know BPs can be the biggest PITAS in the world for no apparent reason when it comes to eating.