Check your bill if you've added TNX to your account they tried charging me an "upgrade support charge" for $20, I called and had them remove it but yeah they say it's "free" but they try to get you on your bill.
Well NSA is no different than LTE when it comes to coverage because NSA uses LTE as an anchor. SA can go further because it doesn't have to rely on LTE.
B71 wouldn't have the same coverage as SA n71 and I didn't do any speed tests I was just referencing the difference in signal strength but both were excellent for what I was doing. I was occasionally connecting to NSA 5G but the signal was equivalent to LTE.