Animation in a template not updated for animation using path - wpf

Question

I have the following XAML that animates a arrow moving on a path for an ESRI Map control. The animation works as expected, except that the animation is not invalidated when the map is zoomed in or out. If I move the animation off screen and back on screen, the animation is correctly re-synced to the scaled path. How do I setup a trigger to force the redraw when the map scale changes?
<esri:LineSymbol x:Key="tunnelSymbol">
<esri:LineSymbol.ControlTemplate>
<ControlTemplate>
<Canvas>
<Path x:Name="Element" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeDashCap="Round" StrokeLineJoin="Round" Opacity="0.5" RenderTransformOrigin="2,0" StrokeThickness="5" Stroke="#FF05AA05">
<Path.Effect>
<DropShadowEffect/>
</Path.Effect>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="SelectionStates">
<VisualState x:Name="Selected">
</VisualState>
<VisualState x:Name="Unselected"/>
</VisualStateGroup>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal">
<Storyboard>
<DoubleAnimation BeginTime="0" Duration="0:0:0.1" Storyboard.TargetName="Element" Storyboard.TargetProperty="(Path.StrokeThickness)" To="5"/>
</Storyboard>
</VisualState>
<VisualState x:Name="MouseOver">
<Storyboard>
<DoubleAnimation BeginTime="0" Duration="0:0:0.1" Storyboard.TargetName="Element" Storyboard.TargetProperty="(Path.StrokeThickness)" To="10"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
</Path>
<Path x:Name="Arrow" Stretch="Fill" Width="16" Height="16" StrokeLineJoin="Miter"
Data="M 0 -5 L 10 -5 M 5 0 L 10 -5 L 5 -10"
Stroke="Black" StrokeThickness="3">
<Path.RenderTransform>
<TransformGroup>
<TranslateTransform X="-8" Y="-8"/>
<MatrixTransform>
<MatrixTransform.Matrix>
<Matrix/>
</MatrixTransform.Matrix>
</MatrixTransform>
</TransformGroup>
</Path.RenderTransform>
<Path.Triggers>
<EventTrigger RoutedEvent="Path.Loaded">
<BeginStoryboard>
<Storyboard>
<MatrixAnimationUsingPath x:Name="MatrixAnimation" Storyboard.TargetName="Arrow"
Storyboard.TargetProperty="RenderTransform.Children[1].Matrix"
DoesRotateWithTangent="True"
Duration="0:0:5"
BeginTime="0:0:0"
RepeatBehavior="Forever" PathGeometry="{Binding Data, Source=Element, BindsDirectlyToSource=True}">
</MatrixAnimationUsingPath>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Path.Triggers>
</Path>
</Canvas>
</ControlTemplate>
</esri:LineSymbol.ControlTemplate>
</esri:LineSymbol>