When one of my pastels was about 3 or so she stopped eating right around Thanksgiving (979 grams). She, up until then, was eating an adult mouse every 5-7 days. She went a full 5 months and nothing which I just chopped up to "normal ball python behavior". On day while talking to a buddy who owns a shop here, he mentioned to try a rat instead......I did and she's been killing them since!
Some of mine like mice and then like rats, others go off rats and start eating mice. Worked for me anytime one of mine goes off food for any considerable amount of time.
Hate to break it to you but I have over 300 rats and 100 mice on hand at all times in my rodent shed.
This isn't picky eater issues.