bug: onStop is being called twice in datafield

The following code of my datafield:

class MyMApp extends Application.AppBase {

    public function onStart(state as Dictionary?) as Void {
        System.println(Time.now().value() + " onStart");
    }

    public function onStop(state as Dictionary?) as Void {
        System.println(Time.now().value() + " onStop");
    }
}

generates such output:

1666566546 onStart
1666566603 onStop
1666566603 onStop
1666566609 onStart
1666566631 onStop
1666566631 onStop
1666566648 onStart
1666566664 onStop
1666566664 onStop

when starting, stopping (and saving)

then starting, stoping (and resuming) and stoping and saving

As you can see onStop is always being called twice in the same second.