I should be used to this but it just annoys me to no end. Without fail, every year, my girl goes off feed for 6-9 months. Always starts in Sept and start eating again anywhere from April to June.
My boy will occasional fast but not like her. I don't change anything ever. Heat and humidity are spot on.
Maybe she can detect pressure changes or some other seasonal cues. Who knows. I know she'll start eating again but it just always drives me nuts.