Wifi on T-Mobile Home Internet

In a word, no. But there is a workaround. You can create a wireless network on the T-Mobile gateway using the phone app, give it a name that only you know and then Hide the network from advertising. Then, with your mesh network in Access Point Mode, create whatever network you want for your devices. The router would connect to one of the two Ethernet outlets on the back of your router. You'll have lots of “signal” in the air, but it won't make any difference. Users will only be able to see the network on your router.

Also note, you CAN NOT turn off DHCP on the T-Mobile gateway, hence the reason you have to put the router in Access Point Mode.

Good luck!