Internet is connected but there is no gateway?

I am trying to set up a separate network on my home internet. The baby monitor we have needs to operate on 2.4Ghz.

I am on the T-Life app and it when I go to Manage Internet, it asks if my gateway is set up. I said yes and it takes me to the screen telling me to reconnect. I go to the Wifi Settings on my phone, log out, log back in and go back to the app. And there's no changes. I can't go past this screen. 

I put in my IP address to log in as an administrator and it took me ot the T-Mobile Gateway Home and this is what it is showing me 

 

So I decided to select Set Up My Gateway, completed everything and it took me right back to the T-Mobile Internet page on the app where it wants me to connect to the Wi-Fi even though I am already connected.

Very confused as to what is wrong and what I’m doing wrong here.