The "activity completed event" is not fired when clicking the "Save" button in sim

I wrote a small test widget app to get acquainted with the "activity completed event" processing.

In the main app class I have 

    function getInitialView() as Array<Views or InputDelegates>? {
        if (System has :ServiceDelegate) {
            Background.registerForActivityCompletedEvent();
        }

        return [new TestAppView()] as Array<Views or InputDelegates>;
    }

    function onBackgroundData(flag as PersistableType) as Void {
        if (flag) {
            System.println("Activity completed!");
        }
    }

    function getServiceDelegate() as Array<ServiceDelegate> {
        return [new BackgroundDelegate()] as Array<ServiceDelegate>;
    }

and in the BackgroundDelegate class I have

    function onActivityCompleted(activity as { :sport as Sport, :subSport as SubSport }) as Void {
        Background.exit(true);
    }

Then I ran the app in the simulator and clicked "Simulation -> Background Events -> Activity Completed Event" and got "Activity completed!" in the debug console which signifies that the code is written correctly.

But then I hoped to get the same message in the debug console in case I finish the activity using the "Simulation -> Activity Data" functionality. I started the activity playback, then clicked the "Start" button, then the "Stop" button, and finally the "Save" button. But nothing happened, the console was empty. Tried Edge 1030 and Fenix 7 devices in the simulator, behavior for both is the same.

So is it just incorrect/insufficient handling of the "Save" button in the simulator and will the onActivityCompleted() be invoked in the background widget process on the real device?