Animation stops in XAML, what could be wrong?

Question

.NET

Good afternoon.
There is a TabControl with multiple tabs and there are animations in the tabs.
When switching between tabs, the animation slows down, and then stops altogether.
What can be wrong?
If you do not switch between tabs, then everything is fine.

<Image.Triggers>
                <EventTrigger RoutedEvent="Image.Loaded">
                    <EventTrigger.Actions>
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[2].(RotateTransform.Angle)"
                                                 RepeatBehavior="Forever" DecelerationRatio="0"
                                                 AutoReverse="False" FrameworkElement.FlowDirection="RightToLeft">
                                    <EasingDoubleKeyFrame KeyTime="0:0:2.10" Value="0"></EasingDoubleKeyFrame>
                                </DoubleAnimationUsingKeyFrames>
                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger.Actions>
                </EventTrigger>
            </Image.Triggers>
            <Image.RenderTransform>
                <TransformGroup>
                    <ScaleTransform/>
                    <SkewTransform/>
                    <RotateTransform Angle="{Binding Speed, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
                    <TranslateTransform/>
                </TransformGroup>
            </Image.RenderTransform>

Answer 1

<UserControl.Resources>

        <Storyboard x:Key="keyfanStoryboard">
            <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[2].(RotateTransform.Angle)"
                                                 RepeatBehavior="Forever" DecelerationRatio="0"
                                                 AutoReverse="False">
                <EasingDoubleKeyFrame KeyTime="0:0:3.10" Value="360"></EasingDoubleKeyFrame>
            </DoubleAnimationUsingKeyFrames>
        </Storyboard>
        
    </UserControl.Resources>

private Storyboard board = null;
---
        InitializeComponent();
        board = (Storyboard)this.FindResource("keyfanStoryboard");
        board.Begin(Animation);
---
        board.Resume();
---
        board.Pause();

Answer 2

UI thread can be loaded?