[Q] Nexus 6 Not getting LTE AT ALL

Hi, I'm using my nexus 6 which I bought in Asia (as far as I know, there's is no different variant that supports different bands when it comes to the nexus 6) in America with T-Mobile as my provider. I'm getting good signals, however I have never gotten LTE. I thought it was my APN problem, so I changed my APN according to T-Mo's website but still nothing. I then wiped my phone, flashed a new rom and flashed two different radios with clean wipes in between (MDM9625_104651.11.05.17R and MDM9625_104649.09.05.14R), nothing. I then changed my sim with my brothers sim which is getting LTE on the Nexus 5 (we live in the same apartment and run the same data plan), still the same.

Under phone testing, (*#*#4636*#*#), it shows I have HSPAP, but when I change to LTE Only, I get no service AT ALL. It turns into only emergency calls.

Does anyone know what I can do to diagnose or check?
Any answer is appreciated. Thank you!