BP do go off feed and it can be for various reasons such as overfeeding, breeding, husbandry, illness, stress, etc.
Check your temperature and make sure they are 80-84 on the cool side, 90-94 on the warm side, of course this mean you need to have an accurate reading provided by a digital thermometer/hydrometer such as this one.
Check your humidity and make sure it is between 50%-60%
Make sure the enclosure is in a low traffic area.
Make sure your enclosure is the appropriated size, an enclosure that is too big can be overwhelming, and can cause stress overtime.
Make sure your hides are tight enough so your BP can snug in, all sides must be touching your BP's body (Avoid log hides as they do not really provide enough security for a BP).
If you handle your BP often, try to limit handling (Too much handling can cause stress)
BP will also fast to catch up if the prey they have eaten in the past are too big or if you feed too often, try feeding our BP a prey slightly smaller then the girth size, once a week, and nothing bigger then a small rat (4 weeks old) for an adult BP. This will allow your BP to feed with more consistency.
Hope this help.