How is your humidity with that set up? Using exclusively lights for heat can really wreck the humidity in a set up like yours. How are you measuring your humidity? Also, the temps you mentioned in your OP, are those ambient temps, or surface spot temps?

Lots of things you can try in this situation. But if your snake was eating, and now it's not, I would look at the husbandry to make sure everything is spot on. Might want to try one hide on the cool side and one on the warm side. Might want to think about using a UTH on a thermostat to provide some belly heat on the warm side.

And, sometimes they just get bored with F/T. Might want to try live just to kick start the feeding response.