"That's dutch with me" means "That's ok with me". Maybe it's different elsewhere, but you don't hear this expression (with this meaning) very often where I am. I think I've only read or heard it a few times in my life. More often I've heard "That's dutch to me" which means "I don't understand (that)". Or if you're having a meal at a restaurant with a friend and you say "Let's go dutch" which means "Let's split the costs".