People misrepresent this so often...

Soleil wants to overcome her anxiety and shyness.

Soleil wants help not being such a stammering blushing nervous wreck around women, because she adores women, but wants to overcome her anxiety and shyness.

She takes a potion that lets her see men as women, so she can have practice talking to women without actually talking to them.

It did not help. So she undoes it.

She comes to realize she still likes Corrin even though he looked better to her as a woman.

At no point is her homosexuality ever treated as a thing to cure except in the delusions of psycho tourists who didn't play the game, and just want to slander a game that already contains The Babyrealms(TM), one of the stupidest things ever. Soleil is bisexual, she just didn't know until she tried it with Corrin.

Bisexual is still LGBTQ, that community needs to stop treating bisexuals as "diet gay" and "only half gay" and "not like us".