Update:
Spent 30min on phone with support.
After factory reset, admin page can be accessed through routerlogin.com and will be fully functional.
It cannot be accessed through the Nighthawk app unless it is deregistered then the serial number registered under my name.
To deregister, original owner has to call or open a support ticket and provide proof or purchase such as the upc from the bx or receipt...there is no way to do this through the app or website.
