...continued from last entry.
Our friends overnight mailed the router to us. At first we got a "service disconnected" error after installing the new Nomad Internet SIM card. I immediately contacted West_212 and Nomad Internet. They both got back to us right away, suggesting a factory reset. Which we did. That fixed it.
The only thing left to do now is to hook up the Yagi antenna to see if that makes a difference. Don't know when we'll be getting to that.
Will post results when we do!