Background task does note exit correctly ?

Has anyone had problems with background task not exiting correctly. The following test application works fine in the simulator but on my Fenix 5 the onBackgroundData function is not called.The strange part is that the function is called sometimes so it has to be something in my code.

using Toybox.Application;
using Toybox.WatchUi as Ui;
using Toybox.Time.Gregorian as Gregorian;
using Toybox.System as Sys;

var bkgAllowed = false;

class BkgTestApp extends Application.AppBase {

	var dateTimeString;
	var today;

    function initialize() {
        AppBase.initialize();
    	bkgAllowed = (Toybox.System has :ServiceDelegate and Toybox has :Background);
    }

    // onStart() is called on application start up
    function onStart(state) {
    }

    function onStop(state) {
    }

    function getInitialView() {

    	if (bkgAllowed) {
   			Toybox.Background.registerForTemporalEvent(new Toybox.Time.Duration(5 * 60));
   		}

        return [ new BkgTestView() ];
    }
(:background)
    function onBackgroundData(response) {
Sys.println("App: resp: " + response);    
		if (response instanceof Array) {
           	if (response[1]) {
				today = Gregorian.info(Time.now(), Time.FORMAT_MEDIUM);
				dateTimeString = today.hour + ":" + 
								 today.min.format("%02d") + " " +
								 today.day_of_week.toString().substring(0,3) + " " + 
								 today.day + " " + 
								 today.month + " " + 
								 today.year.toString().substring(2,4);		
           		Application.Storage.setValue("lastCharge", dateTimeString);
Sys.println("App: write charge: " + dateTimeString);
           		Ui.requestUpdate();
           	}
		} 
	}
	
(:background)
    function getServiceDelegate(){
        return [new BkgTestBkg()];
    }
}

using Toybox.Background;
using Toybox.System as Sys;

(:background)
class BkgTestBkg extends Toybox.System.ServiceDelegate {

	var response = [0.0, false];
	
	function initialize() {
		Sys.ServiceDelegate.initialize();
	}

    function onTemporalEvent() {
        response[0] = Sys.getSystemStats().battery;
        
        if (Sys.getSystemStats() has :charging) {
        	response[1] = Sys.getSystemStats().charging;
        } else {
        	response[1] = false;
        }

Sys.println("bkg: charging: " + response[1] + " bat: " + response[0]);
        Background.exit(response);
    }
}

using Toybox.Application as App;
using Toybox.WatchUi  as Ui;
using Toybox.System   as Sys;
using Toybox.Graphics as Gfx;

class BkgTestView extends Ui.View {

	var w2;
	var h2;
	var lastCharge = "";

    function initialize() {
        View.initialize();
        w2 = Sys.getDeviceSettings().screenWidth / 2;
        h2 = Sys.getDeviceSettings().screenHeight / 2;
    }

    function onLayout(dc) {
        setLayout(Rez.Layouts.MainLayout(dc));
    }

    function onShow() {
    }

    function onUpdate(dc) {
		dc.setColor(Gfx.COLOR_BLACK, Gfx.COLOR_BLACK);
		dc.clear();
		dc.setColor(Gfx.COLOR_WHITE, Gfx.COLOR_TRANSPARENT);

		if (bkgAllowed) {
        	lastCharge = App.Storage.getValue("lastCharge");

        	if (lastCharge != null and lastCharge.length() > 1) {
        		dc.drawText(w2, h2, Gfx.FONT_SYSTEM_XTINY, "Last charge:",  Gfx.TEXT_JUSTIFY_CENTER | Gfx.TEXT_JUSTIFY_VCENTER);
        		dc.drawText(w2, h2 + Gfx.getFontHeight(Gfx.FONT_SYSTEM_XTINY)*1, Gfx.FONT_SYSTEM_XTINY, lastCharge,  Gfx.TEXT_JUSTIFY_CENTER | Gfx.TEXT_JUSTIFY_VCENTER);
        	} else {
        		dc.drawText(w2, h2, Gfx.FONT_SYSTEM_XTINY, "no charge info found",  Gfx.TEXT_JUSTIFY_CENTER | Gfx.TEXT_JUSTIFY_VCENTER);
        	}
        } else {
        	dc.drawText(w2, h2, Gfx.FONT_SYSTEM_XTINY, "device not supported",  Gfx.TEXT_JUSTIFY_CENTER | Gfx.TEXT_JUSTIFY_VCENTER);
        }
    }

    function onHide() {
    }

}