If your character doesn’t play, the form score isn’t affected. (Don’t rely on the graph on the right, it will always show a dip but its not reflected in your score)
It can be frustrating if your character plays and gets lit up and you see a green dot with a low form score. Should the simulations stop? Yeah, it should, but it doesnt. So the only thing you can do is have “Auto Save” turned off and save your game after every game. IF your character plays and form score was lowered, then you just leave the game without saving.