Catch VisibleRangeChanged Event of DateTimeAxisViewModel

Hi there,
I’m trying to catch a VisibleRangeChanged Event of a DateTimeAxisViewModel, but it is never called.
Strangely, it work’s with a numeric axis viewModel?!
I’m refering to the AxisBinding and Annotation Binding Example in the Examples Suite.
I added a MouseWheelZoomModifier to be able to change the VisibleRange

 <s:SciChartSurface.ChartModifier>
                <s:ModifierGroup>
                    <s:MouseWheelZoomModifier>
                    </s:MouseWheelZoomModifier>
                </s:ModifierGroup>
 </s:SciChartSurface.ChartModifier>

In the InitializeAxes method in SciChartMvvmBindingsViewModel two lines were added to catch the VisibleRangeChanged Event:

            var xNumAxis = new NumericAxisViewModel
            {
                AxisAlignment = AxisAlignment.Bottom,
                AxisTitle = "XAxis",
                DrawMajorBands = false,
                TextFormatting = "0.00#",
                VisibleRange = new DoubleRange(0, 10),
                BorderThickness = new Thickness(3),
                BorderBrush = new SolidColorBrush(Colors.CadetBlue)
            };
            xNumAxis.VisibleRangeChanged += xNumAxis_VisibleRangeChanged; //catch num axis event
            XAxes.Add(xNumAxis);

            var xDateTimeAxis = new DateTimeAxisViewModel
            {
                AxisAlignment = AxisAlignment.Top,
                Id = "DateTimeAxis",
                VisibleRange = new DateRange(new DateTime(2017, 1, 1), new DateTime(2017, 1, 31)),
                StyleKey = "DateTimeAxisStyle"
            };
            xDateTimeAxis.VisibleRangeChanged += xDateTime_VisibleRangeChanged; //catch date time axis event

            XAxes.Add(xDateTimeAxis);

Now, when I change the zoom level I jump into the xNumAxis_VisibleRangeChanged-method, but never in the xDateTime_VisibleRangeChanged-method.