Does T Life Require an Internet Connection?

Early in the T-Mobile Home Internet deployment different bands of the cell tower closest to my house would go down and the only way to get the router to connect to a different band was to reboot the router. That was easy to do thru the T-Mobile Internet app because you could sign into the no-internet-connection router directly. So the problem you seem to be confirming that T-Mobile has created is a router that you can only sign into if you have a good internet connection. First router I've ever used to have this self-inflicted design flaw.