Ok tested with T-Mobile sim that uses T-Mobile billing (different from TNX) and had no issues connection to SA n71 on A32 5g factory unlocked.
Also tried Tello on unlocked S21 Ultra with SA 71 and had no n71 at all.
Found CBRS at another location in Manhattan, but haven't been able to test it just yet. Here's the Streetview.
Plus, one more Sprint convert in the Bronx:
Sprint eNB ?? (40.86715407494202,-73.90311136271255) --> T-Mobile eNB 894795
The one plus used to be good for that, but we're taken over. Trying to do it with a one plus nord 200 5g. Need to back it up to android 11 first because 12 has so many issues. Then ask them to give me the key for the bootloader which takes a week. Then root it. Might take me a while but can keep you posted.
Actually think the issue with n71 is a mvno network restriction. Will try to get a real T-Mobile sim and test it (T-Mobile has not seen fit to move my billing off Sprint nor light up fully upgraded tower for 18 months. Grrr.)