GoogleFi Data SIM on Transit Mini

I’m using the GoogleFi data only SIM in a Transit Mini and observe that it can’t connect to TMobile LTE band 71 (600 MHz) reported in InControl2 screen. I have APN setup to h2g2 and other bands seem to work fine. Is band 71 not supported by the GoogleFi data SIM? Is TMobile refusing GoogleFi connections on this new long-range band?