It may be related to breeding season... but likely to improper husbandry.

Not sure from your responses what you temps and humidity are... unless you are measuring them and controlling for them, then they are subject to any changes in the snakes environment.

If you have a snake with a non-controlled environment... temps go up in the house, temps go up for the snake... temps drop at night... snake's temps drop.

That will trigger cooling and will make your snake go off feed.

You want to create your own weather, measure it, and know exaclty what environment the snake has. You create the thermal gradient and then the snake is free to regulate itself.

Temps are good... medium sized rat... those are non-definitive responses. There are many perceptions of what constitutes a medium sized rat or good temps (not saying those were your exact words).

Better is... "snake's temps are XX on the cool side... XX on the hot side". "The rat offered is XXg in size"...

To get concise answers, you need to provide concise information.

Bruce