One reason could be that T-Mobile limits video streaming resolution based on the subscriber's plan. Only the most expensive plan can stream 4K video, otherwise

One reason could be that T-Mobile limits video streaming resolution based on the subscriber's plan. Only the most expensive plan can stream 4K video, otherwise it will "typically" be limited to 480p. https://www.t-mobile.com/cell-phone-plans?lines=2 https://www.t-mobile.com/cell-phone-plans?lines=2