Apple Watch Series 9
I can't make voice calls
Solution 1 of 7: Flight mode is turned on
You can turn off all wireless connections so your Apple Watch can’t cause any interference with sensitive equipment in a plane or a hospital. You can use many Apple Watch functions when flight mode is turned on, but you can't receive calls or messages.
Press the Side button.
Press the flight mode icon to turn the function on or off.
Press the Side button to return to the home screen.