Home Internet and wifi extender

I was very interested in this discussion as I have an "old" (2015) Netgear AC1200 (EX6150) WIFI Range Extender which I had been using with my AT&T "Internet 24" (24 MBPS) service.  For quite awhile now I've wanted (a) faster internet and (b) to get away from AT&T's email service due to the large amount of spam and junk mail I receive on a daily basis.  Of course, I'm in no way obligated to use AT&T's email but, for me the two are inexplicably linked. 

Anyways, my search led me to find T-Mobile's Home Internet service.  Thus far, my speed tests show the T-Mobile service is running between 5 and 10 times faster than AT&T's advertised rate but, the real test, for me at least, was whether I could connect all my devices.  AT&T's router had 4 Ethernet connections, three of which I used, one for my Tablo TV setup, one for the DVR that my home security cameras are connected to and, the third, my shop.  The Netgear extender is located in my shop about 50 yards (more or less) away from the router and, has always provided reliable Internet service to the shop.  The Extender is connected to the router via an Ethernet cord and using the Extender "Access Point" feature.  So, I wanted to be able to do the same thing with the T-Mobile Gateway.

But, we only have 2 Ethernet ports rather than 3.  Ah, but, we also have a USB-C port beneath the two Ethernet ports.  So, I purchased a Belkin USB-C to Network adapter  https://www.bestbuy.com/site/belkin-usb-c-network-adapter-black/6409320.p?skuId=6409320 and there we go, a 3rd Ethernet port.  Initially, I did have some problems getting the Extender to connect to the T-Mobile Gateway.  I also can no longer longer log-in to the Extender itself for some reason.  So, I brought the Extender into the same room as the Gateway got it to connect and then took it back to the shop, plugged it in and sure enough, Success!!!  Reliable Internet service has been restored.  I don't have the cameras working yet so I can't be absolutely sure the Belkin adapter works but, I can confirm that a WIFI Extender will indeed work with the T-Mobile Gateway if it's connected with an Ethernet cable.