Appears you are missing some ports in your forwarding for xbox
TCP 80
UDP 88
TCP/UDP 53
TCP/UDP 3074
have you been to shields up! and done port tests for these ports to see if they are open?
TCP 80
UDP 88
TCP/UDP 53
TCP/UDP 3074
have you been to shields up! and done port tests for these ports to see if they are open?