Couple of thing here can you elaborate on your setup
Temps, Humidity, type of thermometer/hygrometer, type of hides, size of enclosure etc
While nothing has change sometimes husbandry issues will cause problems overtime.
How much weight has you BP lost exactly? How much did he weight before going of feed how much does he weight now, and when was his last meal?
I can tell you that every single one of my BP that are a year and over are eating right now!
As an owner the first thing to do is to try to find out if there is anything that can be done so your BP resume feeding.