Настраиваемый Datepicker не отображает всплывающий календарь

Я настроил стиль выбора даты, но по какой-то причине, когда я нажимаю на кнопку выбора даты, календарь не всплывает и не активирует подпрограмму мыши.

Если я изменю Button x: Name = "Button" на Button x: Name = "PART_Button", появится всплывающий календарь, но в содержимом TextBlocks будет отображаться: «Показать календарь»

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:controls="clr-namespace:System.Windows.Controls;assembly=PresentationFramework"
xmlns:iPodConv="clr-namespace:Custom_DatePicker.CustomDateConverter"
xmlns:vsm="clr-namespace:System.Windows;assembly=PresentationFramework">        
    <Style x:Key="CustomDatePickerStyle" TargetType="controls:DatePicker">
        <Setter Property="IsTabStop" Value="False"/>
        <Setter Property="Background" Value="#FFFFFFFF"/>
        <Setter Property="Padding" Value="2"/>
        <!--Setter Property="SelectionBackground" Value="#FF444444"/-->
        <Setter Property="BorderBrush">
            <Setter.Value>
                <LinearGradientBrush EndPoint=".5,0" StartPoint=".5,1">
                    <GradientStop Color="#FF617584" Offset="0"/>
                    <GradientStop Color="#FF718597" Offset="0.375"/>
                    <GradientStop Color="#FF8399A9" Offset="0.375"/>
                    <GradientStop Color="#FFA3AEB9" Offset="1"/>
                </LinearGradientBrush>
            </Setter.Value>
        </Setter>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="controls:DatePicker">
                <Grid x:Name="PART_Root">
                    <Grid.Resources>
                        <SolidColorBrush x:Key="DisabledBrush" Color="#8CFFFFFF"/>
                        <ControlTemplate x:Key="DropDownButtonTemplate" TargetType="Button">
                            <Grid>
                                <vsm:VisualStateManager.VisualStateGroups>
                                    <vsm:VisualStateGroup x:Name="CommonStates">
                                        <vsm:VisualStateGroup.Transitions>
                                            <vsm:VisualTransition GeneratedDuration="0"/>
                                            <vsm:VisualTransition GeneratedDuration="0:0:0.1" To="MouseOver"/>
                                            <vsm:VisualTransition GeneratedDuration="0:0:0.1" To="Pressed"/>
                                        </vsm:VisualStateGroup.Transitions>
                                        <vsm:VisualState x:Name="Normal"/>
                                        <vsm:VisualState x:Name="MouseOver">
                                            <Storyboard>
                                                <ColorAnimation Duration="0" Storyboard.TargetName="Background" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)" To="#FF448DCA"/>
                                                <ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[3].(GradientStop.Color)">
                                                    <SplineColorKeyFrame KeyTime="0" Value="#7FFFFFFF"/>
                                                </ColorAnimationUsingKeyFrames>
                                                <ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[2].(GradientStop.Color)">
                                                    <SplineColorKeyFrame KeyTime="0" Value="#CCFFFFFF"/>
                                                </ColorAnimationUsingKeyFrames>
                                                <ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[1].(GradientStop.Color)">
                                                    <SplineColorKeyFrame KeyTime="0" Value="#F2FFFFFF"/>
                                                </ColorAnimationUsingKeyFrames>
                                            </Storyboard>
                                        </vsm:VisualState>
                                        <vsm:VisualState x:Name="Pressed">
                                            <Storyboard>
                                                <ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="Background" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)">
                                                    <SplineColorKeyFrame KeyTime="0" Value="#FF448DCA"/>
                                                </ColorAnimationUsingKeyFrames>
                                                <DoubleAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="Highlight" Storyboard.TargetProperty="(UIElement.Opacity)">
                                                    <SplineDoubleKeyFrame KeyTime="0" Value="1"/>
                                                </DoubleAnimationUsingKeyFrames>
                                                <ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[1].(GradientStop.Color)">
                                                    <SplineColorKeyFrame KeyTime="0" Value="#EAFFFFFF"/>
                                                </ColorAnimationUsingKeyFrames>
                                                <ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[2].(GradientStop.Color)">
                                                    <SplineColorKeyFrame KeyTime="0" Value="#C6FFFFFF"/>
                                                </ColorAnimationUsingKeyFrames>
                                                <ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[3].(GradientStop.Color)">
                                                    <SplineColorKeyFrame KeyTime="0" Value="#6BFFFFFF"/>
                                                </ColorAnimationUsingKeyFrames>
                                                <ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[0].(GradientStop.Color)">
                                                    <SplineColorKeyFrame KeyTime="0" Value="#F4FFFFFF"/>
                                                </ColorAnimationUsingKeyFrames>
                                            </Storyboard>
                                        </vsm:VisualState>
                                        <vsm:VisualState x:Name="Disabled">
                                            <Storyboard>
                                                <DoubleAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="DisabledVisual" Storyboard.TargetProperty="(UIElement.Opacity)">
                                                    <SplineDoubleKeyFrame KeyTime="0" Value="1"/>
                                                </DoubleAnimationUsingKeyFrames>
                                            </Storyboard>
                                        </vsm:VisualState>
                                    </vsm:VisualStateGroup>
                                </vsm:VisualStateManager.VisualStateGroups>
                                <Grid Height="48" HorizontalAlignment="Center" Margin="0" VerticalAlignment="Center" Width="59" Background="#11FFFFFF">
                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition Width="6*"/>
                                        <ColumnDefinition Width="30*"/>
                                        <ColumnDefinition Width="30*"/>
                                        <ColumnDefinition Width="30*"/>
                                    </Grid.ColumnDefinitions>
                                    <Grid.RowDefinitions>
                                        <RowDefinition Height="6*"/>
                                        <RowDefinition Height="20*"/>
                                        <RowDefinition Height="20*"/>
                                        <RowDefinition Height="30*"/>
                                    </Grid.RowDefinitions>
                                    <Border x:Name="Highlight" Margin="-1" Opacity="0" Grid.ColumnSpan="4" Grid.Row="0" Grid.RowSpan="4" BorderBrush="#FF6DBDD1" BorderThickness="1" CornerRadius="0,0,1,1"/>
                                    <Border x:Name="Background" Margin="0,-1,0,0" Opacity="1" Grid.ColumnSpan="4" Grid.Row="1" Grid.RowSpan="3" Background="#FF1F3B53" BorderBrush="#FFFFFFFF" BorderThickness="1" CornerRadius=".5"/>
                                    <Border x:Name="BackgroundGradient" Margin="0,-1,0,0" Opacity="1" Grid.ColumnSpan="4" Grid.Row="1" Grid.RowSpan="3" BorderBrush="#BF000000" BorderThickness="1" CornerRadius=".5">
                                        <Border.Background>
                                            <LinearGradientBrush EndPoint=".7,1" StartPoint=".7,0">
                                                <GradientStop Color="#FFFFFFFF" Offset="0"/>
                                                <GradientStop Color="#F9FFFFFF" Offset="0.375"/>
                                                <GradientStop Color="#E5FFFFFF" Offset="0.625"/>
                                                <GradientStop Color="#C6FFFFFF" Offset="1"/>
                                            </LinearGradientBrush>
                                        </Border.Background>
                                    </Border>
                                    <Rectangle StrokeThickness="1" Grid.ColumnSpan="4" Grid.RowSpan="2" Margin="0,0,0,2">
                                        <Rectangle.Stroke>
                                            <LinearGradientBrush EndPoint="0.48,-1" StartPoint="0.48,1.25">
                                                <GradientStop Color="#FF494949"/>
                                                <GradientStop Color="#FF9F9F9F" Offset="1"/>
                                            </LinearGradientBrush>
                                        </Rectangle.Stroke>
                                        <Rectangle.Fill>
                                            <LinearGradientBrush EndPoint="0.3,-1.1" StartPoint="0.46,1.6">
                                                <GradientStop Color="#FFBD4A40"/>
                                                <GradientStop Color="#FFEAAFAF" Offset="1"/>
                                            </LinearGradientBrush>
                                        </Rectangle.Fill>
                                    </Rectangle>
                                    <TextBlock
                                                HorizontalAlignment="Center" 
                                                VerticalAlignment="Center" 
                                                DataContext="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=.Content}"
                                                Text="{Binding Converter={StaticResource DateTimeFormatter}, ConverterParameter=DOW}"
                                                FontSize="11" Margin="0,0,0,3"
                                                Grid.Column="0" 
                                                Grid.ColumnSpan="4" 
                                                Grid.Row="0" 
                                                Grid.RowSpan="2" 
                                                />
                                    <TextBlock
                                                HorizontalAlignment="Center" 
                                                VerticalAlignment="Center" 
                                                DataContext="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Content}"
                                                Text="{Binding Converter={StaticResource DateTimeFormatter}, ConverterParameter=MMMM}"
                                                FontSize="10" Margin="0,10,0,3"
                                                Grid.Column="0" 
                                                Grid.ColumnSpan="4" 
                                                Grid.Row="1" 
                                                Grid.RowSpan="2" 
                                                />
                                    <TextBlock
                                                HorizontalAlignment="Center" 
                                                VerticalAlignment="Bottom" 
                                                DataContext="{Binding Path=Content, RelativeSource={RelativeSource TemplatedParent}}"
                                                Text="{Binding Converter={StaticResource DateTimeFormatter}, ConverterParameter=dd}"
                                                FontSize="26" Margin="0,0,0,-3" 
                                                Grid.Column="0" 
                                                Grid.ColumnSpan="4" 
                                                Grid.Row="2" 
                                                Grid.RowSpan="2" />
                                    <Border x:Name="PART_DisabledVisual" Opacity="0" Grid.ColumnSpan="4" Grid.Row="0" Grid.RowSpan="4" BorderBrush="#B2FFFFFF" BorderThickness="1" CornerRadius="0,0,.5,.5"/>
                                </Grid>
                            </Grid>
                        </ControlTemplate>
                    </Grid.Resources>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*"/>
                        <ColumnDefinition Width="Auto"/>
                    </Grid.ColumnDefinitions>
                    <vsm:VisualStateManager.VisualStateGroups>
                        <vsm:VisualStateGroup x:Name="CommonStates">
                            <vsm:VisualState x:Name="Normal"/>
                            <vsm:VisualState x:Name="Disabled">
                                <Storyboard>
                                    <DoubleAnimation Duration="0" Storyboard.TargetName="DisabledVisual" Storyboard.TargetProperty="Opacity" To="1"/>
                                </Storyboard>
                            </vsm:VisualState>
                        </vsm:VisualStateGroup>
                    </vsm:VisualStateManager.VisualStateGroups>
                    <Button x:Name="Button" Grid.Column="0" Grid.ColumnSpan="4"
                                Content="{TemplateBinding SelectedDate}"
                                Template="{StaticResource DropDownButtonTemplate}"
                                Margin="2,0,2,0" 
                                Width="60" 
                                BorderBrush="{TemplateBinding BorderBrush}" 
                                BorderThickness="{TemplateBinding BorderThickness}" 
                                Foreground="{TemplateBinding Foreground}"/>
                    <Grid x:Name="DisabledVisual" IsHitTestVisible="False" Opacity="0" Grid.ColumnSpan="2">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="*"/>
                            <ColumnDefinition Width="Auto"/>
                        </Grid.ColumnDefinitions>
                        <Rectangle Fill="#8CFFFFFF" RadiusX="1" RadiusY="1"/>
                        <Rectangle Fill="#8CFFFFFF" RadiusX="1" RadiusY="1" Height="18" Margin="2,0,2,0" Width="24" Grid.Column="1"/>
                    </Grid>

                    <Popup x:Name="PART_Popup"
                           PlacementTarget="{Binding ElementName=Button}"
                           Placement="Bottom" 
                           StaysOpen="False"
                           AllowsTransparency="True" 
                           PopupAnimation="Slide"
                           Focusable="True" />
                </Grid>
            </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>

Любая помощь будет принята с благодарностью.