My freind and I both have open NAT but cannot connect to eachother in any game. We can only be in a party if another person is with us in that party as soon as they leave it kicks both of us also. It was not always like this we used to be able to connect just fine. There is only this one freind that it does not work with. He just recently got a new internet service the same time this started happening. But he can connect just fine to basicly everyone else.