Why TMobile is down today?

I don't know where you're located, but this started happening in Austin, TX a few weeks ago. After multiple calls to customer service they finally said that they are "modernizing" the nearby tower and their only suggestion was to buy a new phone, even though mine is listed as fully compatible on their website! I'm not willing to do that since it still works fine on other towers. I have resigned myself to using "wifi calling" while at home and the network elsewhere. But it's a pain because I have to switch back and forth manually every time I leave or return home.