Noesis does not support RemoveStoryboard: https://docs.microsoft.com/en-us/dotnet/api/system.windows.media.animation.removestoryboard?view=netframework-4.8

RemoveStoryboard is commonly used in control template triggers, as shown below:

<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsMouseOver" Value="False"/>
<Condition Property="IsFocused" Value="True"/>
<Condition Property="IsPressed" Value="False"/>
</MultiTrigger.Conditions>
<MultiTrigger.Setters>
<Setter TargetName="PART_Image" Property="Source" Value="{DynamicResource _FocusedImage}"/>
<Setter TargetName="PART_Image" Property="Opacity" Value="1"/>
</MultiTrigger.Setters>
<MultiTrigger.EnterActions>
<BeginStoryboard x:Name="PART_Focus_Storyboard">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="PART_Image" Storyboard.TargetProperty="(Rectangle.Opacity)" From="0.5" To="1.0" Duration="0:0:0.5" RepeatBehavior="Forever" AutoReverse="True"/>
</Storyboard>
</BeginStoryboard>
</MultiTrigger.EnterActions>
<MultiTrigger.ExitActions>
<RemoveStoryboard BeginStoryboardName="PART_Focus_Storyboard"/>
</MultiTrigger.ExitActions>
</MultiTrigger>

Please correct me if I am wrong -- without RemoveStoryboard there is no mechanism to end an animation on trigger exit.