Tbh I only can think of one. For whatever reason I used to not like Wonwoo from Seventeen cuz I thought everyone just biased him for no reason (don't come at me I literally knew nothing abt Seventeen) but soon I heard his low voice and now he's one of my bias wreckers in Seventeen.
I used to dislike Haechan because I thought he was too loud and I didn't like his vocal tone.
But now he's my ult bias in all of kpop and I love those things about him.
I used to kinda dislike Nayeon cause my first twice bias was Jeongyeon and I was angry that they had the same position but nayeon had a lot more lines and just attention in general
Now I learned more about why this happens and it doesn’t bother me anymore and I love nayeon!
I used to dislike Yiren from EVERGLOW because she wasn't even trying to sing on some stages compared to the other members, but she's good now Also, I didn't like Nancy from MOMOLAND because of all the stupid rumors and false accusations around her, now I feel so bad because she's actually a pretty sweet girl imo