Hi and good day, thanks for reaching out and sorry for all the trouble. In my experienced, this is the sequence i used: RC-AC-APP. For the shut down process, the drone should be shut down first before the remote controller. In your case, I would recommend you back up your files and sync your flight records and then reinstall the app. After that, kindly re-link the RC to your AC. Do all the features work? May I know if the firmware is up to date? You can also try to use a different mobile device so that we can isolate the issue. Appreciate your support.