Perfect husbandry to me means nothing not knowing who you have talk to to set up your husbandry, what is perfect for one snake is not always perfect for the other so in an effort to provide you with an OPTIMAL setup for your animal details will be needed.
Can you give us details on your snakes very specific ones?
One did you contact the breeder so it could help you troubleshoot the issue?
First the prey size is an issue pinky and fuzzy mice are way too small for any BP even an hatchling get started on something bigger.
Age and weight?
Enclosure type and size?
Hides? Are they tight?
Temperature?
Have you been handling the animal? How often?
What do you know of the history of the snake? Was he eating F/T or live, this makes a big difference as trying to switch an animal upon reception if often a guaranteed failure.