Xbox 360 acadyan gateway issue. trying to set up a router using ethernet, still no luck

I have an original series xbox 360 and have tried many times over to connect to xbox live. i can connect to the network, even download games. but for whatever reason my connection is being blocked on the gateway when trying to play online. i keep receiving an mtu error and internet: failed Xbox Live: Blocked.

i tried wireless and ethernet, manual setup and automatic. tried changing dns ports.

i tried setting up a router in-between the xbox and gateway router, setting static ip

not really sure what else i can try

all suggestions would be very welcomed