Can not drag AxismarkerAnnotation in VerticallyStackedAxes correctly

I use VerticallStackedAxes of SciChart component and add 7 AxisMarkerAnnotation to each NumericAxis but AxisMarkerAnnotations not draggable except first of them.

this is the part of my UserControl code:

<s:SciChartSurface.YAxes>








</s:SciChartSurface.YAxes>

        <s:SciChartSurface.ChartModifier>
            <s:ModifierGroup>
                <s:RubberBandXyZoomModifier IsXAxisOnly="True"/>
                <s:ZoomExtentsModifier/>
                <s:CursorModifier ShowAxisLabels="False" ShowTooltip="False"/>
            </s:ModifierGroup>
        </s:SciChartSurface.ChartModifier>

        <s:SciChartSurface.Annotations>

            <!-- Draws Bands behind each axis -->
            <s:BoxAnnotation YAxisId="Ch0" CoordinateMode="RelativeX" X1="0" X2="1" Y1="{Binding VisibleRange.Min, ElementName=Ch0}" Y2="{Binding VisibleRange.Max, ElementName=Ch0}" Background="#11000000" AnnotationCanvas="BelowChart"/>
            <s:BoxAnnotation YAxisId="Ch1" CoordinateMode="RelativeX" X1="0" X2="1" Y1="{Binding VisibleRange.Min, ElementName=Ch1}" Y2="{Binding VisibleRange.Max, ElementName=Ch1}" Background="#44B0C4DE" AnnotationCanvas="BelowChart"/>
            <s:BoxAnnotation YAxisId="Ch2" CoordinateMode="RelativeX" X1="0" X2="1" Y1="{Binding VisibleRange.Min, ElementName=Ch2}" Y2="{Binding VisibleRange.Max, ElementName=Ch2}" Background="#11000000" AnnotationCanvas="BelowChart"/>
            <s:BoxAnnotation YAxisId="Ch3" CoordinateMode="RelativeX" X1="0" X2="1" Y1="{Binding VisibleRange.Min, ElementName=Ch3}" Y2="{Binding VisibleRange.Max, ElementName=Ch3}" Background="#44B0C4DE" AnnotationCanvas="BelowChart"/>
            <s:BoxAnnotation YAxisId="Ch4" CoordinateMode="RelativeX" X1="0" X2="1" Y1="{Binding VisibleRange.Min, ElementName=Ch4}" Y2="{Binding VisibleRange.Max, ElementName=Ch4}" Background="#11000000" AnnotationCanvas="BelowChart"/>
            <s:BoxAnnotation YAxisId="Ch5" CoordinateMode="RelativeX" X1="0" X2="1" Y1="{Binding VisibleRange.Min, ElementName=Ch5}" Y2="{Binding VisibleRange.Max, ElementName=Ch5}" Background="#44B0C4DE" AnnotationCanvas="BelowChart"/>
            <s:BoxAnnotation YAxisId="Ch6" CoordinateMode="RelativeX" X1="0" X2="1" Y1="{Binding VisibleRange.Min, ElementName=Ch6}" Y2="{Binding VisibleRange.Max, ElementName=Ch6}" Background="#11000000" AnnotationCanvas="BelowChart"/>
            <s:BoxAnnotation YAxisId="Ch7" CoordinateMode="RelativeX" X1="0" X2="1" Y1="{Binding VisibleRange.Min, ElementName=Ch7}" Y2="{Binding VisibleRange.Max, ElementName=Ch7}" Background="#44B0C4DE" AnnotationCanvas="BelowChart"/>

            <s:AxisMarkerAnnotation X1="0.0" 
                                    Y1="0.0"
                                    YAxisId="Ch0"
                                    IsEditable="True"
                                    LabelTemplate="{StaticResource AxisMarkerTemplate}"
                                    PointerTemplate="{StaticResource DefaultAxisPointerTemplate}"/>

            <s:AxisMarkerAnnotation X1="0.0" 
                                    Y1="0.0"
                                    YAxisId="Ch1"
                                    IsEditable="True"
                                    LabelTemplate="{StaticResource AxisMarkerTemplate}"
                                    PointerTemplate="{StaticResource DefaultAxisPointerTemplate}"/>
        </s:SciChartSurface.Annotations>

You can find source code Here
thanks