From what I've heard after they've become sexually mature they can sometimes fast.

I had my female go off feed once and I didn't like that much so I ended up completely changing it up. I went from a glass tank to a boaphile 421D. She was also starting to outgrow her hides so I got bigger ones.

I forget where or who said this on the forums, but a warm snake is a hungry snake. So try boosting up the temps a little.

My female eventually took a mouse, and was more intimidated by the bigger rats. So also try smaller prey items and work her way back up.