Stop eating

I was watching a video on youtube from theserpentchamber and he said that some ball pythons go off feed when they hit the 400 gram range or so. Could this be what is happening to my ball python? she is 390 grams empty and stopped eating for me for over 3 weeks.

Ball Pythons will go off feed at random times in their lives.
It all depends on the snake. It may be some peoples exerience that they go off feed at 400g. I know i had a female mojave shipped to me June and she JUST ate her first meal for me 2 weeks ago. She is the only snake Ive had a problem with getting to feed, and shes 450g.
It can have to do with many factors...shipping, moving, new lighting, different temps, hormones. etc.
In my experience a fast rarely gets really serious or dangerous. Sometimes you have to feed them live to snap them out of their fast.
But just keep offering them their prey every week and one day she will feel like it again.

It all depends, what is your husbandry like? What prey/size, and how often were you feeding? were you feeding live or f/t?