If all of your husbandry perimeters are within spec you can start the usual list of alternatives to stimulate feeding. Live mice of various colors are the usual first step. You can then turn to african soft fur rats, gerbils and even hamsters and chics. Bps are known for hunger strikes. Worst case scenario you can visit an exotic vet who can feed the snake by gavage to provide nutrients. Just be patient. Ive seen Bps go 1.5 years without food. Definitely not good for that, but they will survive. Provide plenty of water.