Tmobile 5g home internet + Xbox Series X not compatible

Javiair wrote:

Thanks to T-Mobile's Test Drive, I can try out the home internet for 15days. I'm getting good speeds and so far so good… I was really happy with the service until………

It's not compatible with my Xbox Series X. Apps like YouTube, Twitch, Hulu all work. But if I want to play games online, that's where it doesnt work. I get disconnected from the games respective servers. Doing a test on the network I get UPnP unavailable. I can retest until the UPnP is available but as soon as I start playing a game online, it disconnects. 

I see that I can attempt to connect a wireless router but I cannot control any settings on the App or if I log into router via a web browser. The only thing I can do is change names and passwords, but nothing else. Can a wireless router be connected to the gateway? If so, which brands will work best?

There are other posts about this issue but no answer. I hope there is a solution or else the home internet goes back to T-Mobile and they will lose out on $50/month. 

We just connected an ethernet cable from the Xbox to the TV and it works fine.