5G Gateway Setup with Smart TV

@KHNC -- is your TV in a good location relative to the gateway?  Use the Speedtest app on your phone and hold it near the back of the TV to check your Wi-Fi signal there.  If the download speed isn't good, you will have to move the gateway and/or the TV.

If the Wi-Fi seems good, please try this:

Some devices cannot see or connect to the gateway's default network.  You want to leave this network alone and AGREGAR a second network with the + sign at the bottom of the Network tab in the T-Mobile Internet app.  For this new network, set the band to 2.4 GHz and set the WPA version to WPA/WPA2.  Try connecting your TV to this second network.  Use the default network for your other devices, as much as possible.

Here are the T-Mobile support instructions for how to add the second network with the app.

Android  How to create additional Wi-Fi networks | App T-Mobile Internet | Android | Asistencia de T-Mobile

iOS  How to create additional Wi-Fi networks | App T-Mobile Internet | iOS | Asistencia de T-Mobile

And if you still can't connect, you don't have to buy another TV.  Get a separate streaming device such as an Amazon Fire TV Stick or a Roku Stick or Express 4K+.  Most people have no trouble getting them to connect to the gateway's default network.  If your Wi-Fi isn't strong near the TV, I recommend the Roku Express 4K+ because it has a longer HDMI cable so you can move it away from the back of the TV.