Thanks, Taylor.
It is "host". Alas...I forgot to use /all when I ran ipconfig. I assume the "missing" IP would have been covered by /all if I had done so.
I think I am able to explain the problem now. Our app does not have a TURN configured, thus is forced to use the udp/tcp candidates within the Starbucks network. Somehow, the Starbucks perhaps does not allow udp, tcp or both on some ports. Then, the ICE has no choice but to fail.
I tried the WebRTC demo and it worked well. I observed the two devices on the same coffee table using the same Starbucks WiFi were forced to use relay with a "peerreflexive" type!!