It seems that the only way to locate the hub when it's connected to a phone hotspot in an area with no Internet service is to use a deprecated LAN scanner app or root the phone.
It would be great if the “find" function in the Android Hubitat app could be improved to function totally locally so I could find my hub on my hotspot when I don't have Internet access.
The Advanced Find function works fine WITH Internet access, but does nothing (no response) without Internet access.