We have found the issue of missing airports after install the UK scenery. The download of the UK package was broken on a few servers. As a workaround we recommended to completely uninstall Aerofly FS 2021 and download it again from the iOS App Store.
We apologise for the inconvenience.
Everything seems fixed, even the battery drain problem! Thank you developers!!! Now the simulator is perfect. We need only new airplanes add ons... Keep up the good work!