This is known as the black floor. Just go into Settings -> General -> and Clear Cache. Do it more than once if the scenery doesn’t reload/refresh.
Restart your device occasionally before flights
Keep a stable internet connection
Reset your router
Edit: I’m off to Zzzz. If the scenery doesn’t return after clearing cache we recommend that you close the app, power down your device and then reboot. Kind Regards, Chris
Ok thank you very much.
Jut let us know if this resolves the issue. ;)