How do i animate a Border inside Itemscontrol?

[Guacamole-1]

i have this ItemsControl:

<StackPanel Grid.Column="1" Grid.Row="0" HorizontalAlignment="Center" Name="Votes"
                        Orientation="Horizontal"
                        Margin="0,0,0,10">
                <ItemsControl ItemsSource="{Binding Judges}" x:Name="JudgeItemsControl">
                    <ItemsControl.ItemsPanel>
                        <ItemsPanelTemplate>
                            <StackPanel Orientation="Horizontal"/>  <!-- força layout horizontal-->
                        </ItemsPanelTemplate>
                    </ItemsControl.ItemsPanel>
                    <ItemsControl.ItemTemplate>
                        <DataTemplate>
                            <Grid RowDefinitions="*,Auto" Height="110">
                                <TextBlock Text="{Binding Label}" Width="180"  VerticalAlignment="Bottom"  Margin="0,0,0,10"  TextWrapping="Wrap" FontSize="25" TextAlignment="Center" Foreground="White" />
                                <Border Grid.Row="1" Width="140" Height="30" x:Name="JudgeRect"
                                        Background="{Binding Votecolour}"
                                        Margin="40,0" CornerRadius="10"
                                        Padding="0" Classes="Animation">
                                    <Border.RenderTransform>
                                        <ScaleTransform ScaleX="1.0" ScaleY="1.0" />
                                    </Border.RenderTransform>
                                </Border>
                            </Grid>
                        </DataTemplate>
                   </ItemsControl.ItemTemplate>
                </ItemsControl>
            </StackPanel>

and i want to apply this animation to the Border,

private async void PulseAnimation(Control control)
        {
            if (control?.RenderTransform is not ScaleTransform)
            {
                // Ensure there's a ScaleTransform to animate
                control.RenderTransform = new ScaleTransform(1.0, 1.0);
            }
            
            var animation = new Animation
            {
                Duration = TimeSpan.FromSeconds(0.7),
                Children =
                {
                    // Start: scale 1.0
                    new KeyFrame
                    {
                        Cue = new Cue(0.0),
                        Setters =
                        {
                            new Setter(ScaleTransform.ScaleXProperty, 1.0),
                            new Setter(ScaleTransform.ScaleYProperty, 1.0)
                        }
                    },
                    // Mid: scale 1.5
                    new KeyFrame
                    {
                        Cue = new Cue(0.5),
                        Setters =
                        {
                            new Setter(ScaleTransform.ScaleXProperty, 1.5),
                            new Setter(ScaleTransform.ScaleYProperty, 1.5)
                        }
                    },
                    // End: back to 1.0
                    new KeyFrame
                    {
                        Cue = new Cue(1.0),
                        Setters =
                        {
                            new Setter(ScaleTransform.ScaleXProperty, 1.0),
                            new Setter(ScaleTransform.ScaleXProperty,1.0)
                        }
                    }
                }
            };
            
            await animation.RunAsync(control);
        }

i already have this animation for a textblock and is working, and want to apply to the border too, but i tried this and it isnt working

private void OnAnimationRequest(object? sender, string e)
      {
          Dispatcher.UIThread.Post(() => PulseAnimation((e switch
          {
              "Blue" => BluePoints,
              "Red" => RedPoints,
              "Judge" => GetJudgeRect((Judge)sender!),
              _ => throw new ArgumentOutOfRangeException(nameof(e), e, null)
          })!));
      }

      private Border? GetJudgeRect(Judge judge)
      {
          var container = JudgeItemsControl.ContainerFromItem(judge);
          if (container is Control control)
          {
              var cntrl = control.FindControl<Border>("JudgeRect");
              return cntrl;
          }
          return null;
      }

when i do debugging i find that cntrl is null, could someone help? I cant really find nothing on animations in avalonia.
thank you