R7450 cant IP into router because it tries to register but its already registered and its an endless

when i ip into my router it goes to the internet and wants to register my modem. once there it find that its already registered and goes into an endless do loop you cant get out of. i have reset and set up the router over and over same issue .  only way i can get into router is diconnect internet and it seems to time out and then function normal .  stared after the firmware update .  im just about done with netgear and their poor support or lack of ...