She specifically said she learned stuff about herself in France and they just weren't a good fit, the clear meaning is "because you're a dude". The implication is she is a full blown lesbian. Of course this is inconsistent with her previous portrayal where she showed physiological signs of arousal at Marco, like her pupils getting really big, she was comfortable being physical with Marco, draping her legs over his crotch, she had a previous male crush at skate camp, etc.
The obvious answer to this question is: THE COTUGNO SEASONS AREN'T CANON. Only season 1 and 2 and Battle for Mewni are canon. The rest is like a whole different show, contradicting and ruining everything from the real show.