I am submitting this question with airplane mode on but wifi enabled.
When I attempt to make a call with airplane mode on and wifi enabled, I get the message “Connect to wifi to make calls. Cellular network not available. Connect to wifi to make calls.”
To be clear: I am connected to a wifi network when this message appears: the Republic app thinks so, and the phone wifi setting thinks so. …For that matter, so does my browser, where I’m typing this question.