Rapidring app won’t connect over cellular on iPhone (iOS 14.2)

I have a Spotlight Cam wired. If I get a notification from Rapidring on my iPhone SE 2020 or my wife’s iPhone 8Plus, I can view video quickly and perfectly over Home wifi with the Rapidring app but it never establishes a connection when away from the home, or even in the home using 4G cellular (i.e not connected to wifi). The camera has good wifi (RSSI -37), the Wifi Mesh Extender is almost underneath the camera with a wooden wall in between (very close), the bandwidth readings for the camera are d/l 42Mbps and u/l 4Mbps. Why won’t Rapidring connect when away from home on 4G cellular? I have uninstalled/reinstalled the app to no effect.