Hello, new Mavic Air owner here. When my phone is connected to the remote via the cable, is my phone also supposed to be connected to the drone's wifi at the same time? Is it one or the other or both at the same time?
No, just connect it with the cable and don't worry about anything else. I even like to put my phone to Airplane mode, just to be sure I'm not distracted by any incoming messages, calls, whatever. The WiFi part is done between RC and AC, phone doesn't matter.