I disagree the temps are low in the enclosure, the snake could get an RI and the snake might be going off feed from it, it doesnt matter what the weather is you should supply enough heat to heat properly.
Also snakes in Africa live inside termite mounds and abandoned rodent dens, they live very secretive lives inside very small cramped spaces, so the enclosure can be too large with too much open space so the snake doesnt feel secure... Another reason the snake might have gone off feed...