I don't know if it's a bug or it should be like that, but while being marked as contributor to the game we submitted with a friend, I can't rate other games, it says I have not submitted anything. But when I leave a comment it clearly says "Submitted:..." under my comment. Is there something to do with it?

I'm experiencing the same thing! I was about to ask this as well

Had the wrong setting ticked. Changed it now contributors should be able to rate.