Would try to show an image to try and help but itch isn't having it. I'll give it another go in the morning. Awesome game none-the-less and is the first RPG I've honestly enjoyed, not just because of the fetish content but because of the character design and development.
I have no idea what would cause this. Try using the replay mode on the PC and going through the Play As Madison fight in the training area again. If that doesn't work you'd have to reload a save from before it broke.
Looking into this, the only way it'd happen is if you managed to KO Amber in the sparring match before it's supposed to end. This *should* be completely impossible. Did you pull it off somehow?