Using the battery on iPad mini even when not in use

The app keeps using the location and using the battery even if “takeoff” mode is not in use, and even if the app is killed on the iPad.
This seems like a major bug to me.

Only way to prevent this that I’m aware of is revoking the location permission every time I stop using the app.

I have the same problem with my IPhone 16. Battery consumption of the SafeSky app continuing after the flight even though the app was killed. Background activity 21/24h indicated in the Battery section of the settings.