Well, the title is self-explanatory. I stop the game, it immediately started again and my save for the Arcade mode was deleted. The Story mode seems to be fine.
It wasn't too hard to get those 3 stars but it's annoying to see them deleted 3 maps before the end. Besides, my scores are still there. It looks stupid.

Is there a way to get my save back or do I have to restart? Rebooting Steam didn't work.
I guess I'm not the only one anyway.