Have you actually looked in the custom folder where MSFS saves it?
Microsoft Store
C:\Users\YourName\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\SimObjects\Airplanes\Aerosoft_CRJ_550 ( or Aerosoft_CRJ_700 )
Steam
C:\Users\YourName\AppData\Roaming\Microsoft Flight Simulator\SimObjects\Airplanes\Aerosoft_CRJ_550 ( or Aerosoft_CRJ_700 )
So if you have a cfg inside those folders then you need to check W10 is not preventing you from editing them. Check you have Admin rights to AppData. Also right click cfg/properties and make sure read only is not ticked.