Regardless what some other folks say, I always start out with my phone connected to the Internet.
Or, if I'm using my WiFi-only tablet, I use the phone's hot spot to connect to the tablet's WiFi. That way, the GO App gets the latest information, as well as allowing Google maps to load and set the home-point correctly.
Then, after everything has initialized (either before or after takeoff), sometimes I switch into airplane mode to reduce the processing load on the phone. But when I've forgotten, I've never had a serious problem.
Bear Mountain, try connecting everything on your kitchen table without the props, with the phone connected to the Internet, and give it a few minutes to settle in, perhaps. You could even start and kill the engines a couple of times, just to test the entire system, and to adjust the app settings to your liking.