t-mobile Home Internet - Location Issue

Not defending TMO since they should be able to better explain this phenomenon by themselves... but this really is the fault of content providers that rely on IP-based  geolocation databases. In a wired world they are accurate but with mobile and satellite technologies your location can be very far away from your network's point of presence, as noted by Cali Cat above. There's nothing in an IP address that identifies your location accurately - the only location that is 100% certain from your IP address is your country (unless using a VPN).

Content providers that rely on  GPS based location are generally accurate but even then there are ways to fake them out or spoof (giving you more flexibility) but not all devices have GPS capability and methods as described buy Cali Cat for YTTV may be available from your content provider.