maybe in other country it works, but in US T-Mobile use Band n71 (600 MHz) Band n41 (2.5 GHz) Band n260 (39 GHz) Band n261 (28 GHz) for 5G and our international XPERIA 1 ii only have 1, 3, 28, 77, 78 NSA/Sub6. oh i just realized the 4G band on our phones are: 1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 19...