Press and hold the "volume knob", just below the infotainment screen, for 3-5 seconds until your infotainment system rebootI haven't been able to connect to the car via the MyNissan app for several days, and on the infotainment screen it shows full service for cell, but then next to it is an icon of a car with a slash through it. I've tried resetting NissanConnect from the settings menu, which resulted in an error and that's it.
Most EV's I've had or been around let you do a full reboot / at least restart cellular. Hopefully there is a solution beyond taking it into service.
Resetting the infotainment did not help to restore the cell reception back. It all depends on the ATT cellular 4G network availability. The connection restores itself after few hours.Press and hold the "volume knob", just below the infotainment screen, for 3-5 seconds until your infotainment system reboot