Gaming

If you search NAT in this forum, you'll see that your situation is not unique. Without boring you with details, T-Mobile Home Internet (TMHI) does not support NAT, and does not allow you access to the gateway to make any changes like DHCP, NAT or DNS.

That’s because TMHI is a Fixed Wireless Access network that is different from an ISP like Xfinity. Xfinity gives you a local external IP address. FWA networks like T-Mobile give you an external IP that is most likely nowhere near where you are using the product. As an example, I live in S. Florida but my external IP resolves to Bellingham WA. One way to change that is to use a VPN, like Mullvad VPN. That will change your IP to a geographically local IP, but it won't fix your problem with trying to create a NAT for your Xbox.

You might want to check out Nater Tater on YouTube who has some workarounds, but they aren't for the faint-of-heart. Unfortunately, it may be that TMHI won't work for you based on your needs.

Good luck!