Почему не записываются данные в ComboBox?

При выбери из списка значений, комбо бокс на себе не отображает выбранное.

Получение данных

cBRole.ItemsSource = LibraryEntities.GetContext().Roles.ToList();

Стиль

<Style TargetType="ComboBox">
        <Setter Property="Width" Value="150"></Setter>
        <Setter Property="Height" Value="30"></Setter>
        <Setter Property="HorizontalContentAlignment" Value="Left"></Setter>
        <Setter Property="VerticalContentAlignment" Value="Center"></Setter>

        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ComboBox}">
                <Grid>
                    <ToggleButton Width="10" Height="30" VerticalAlignment="Center" HorizontalAlignment="Right" Focusable="False" Panel.ZIndex="1"
                                        IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
                                          Background="Transparent"
                                          Margin="10"
                                BorderThickness="0">
                        <Path HorizontalAlignment="Center" VerticalAlignment="Center" Data="M 0 0 L 4 4 L 8 0 Z">
                            <Path.Fill>
                                <SolidColorBrush Color="Black"/>
                            </Path.Fill>
                        </Path>
                    </ToggleButton>
                    <Border Name="border" CornerRadius="20" Padding="2" Background="White" BorderThickness="2" BorderBrush="DarkBlue">

                    </Border>
                    <Popup x:Name="Popup" Placement="Bottom" IsOpen="{TemplateBinding IsDropDownOpen}" Focusable="False" PopupAnimation="Slide">
                        <Grid x:Name="DropDown" SnapsToDevicePixels="True" MinWidth="{TemplateBinding ActualWidth}" MaxHeight="{TemplateBinding MaxDropDownHeight}">
                            <Border x:Name="DropDownBorder" BorderThickness="1">
                                <Border.BorderBrush>
                                    <SolidColorBrush Color="{TemplateBinding BorderBrush}" />
                                </Border.BorderBrush>
                                <Border.Background>
                                    <SolidColorBrush Color="#CEE3FF" />
                                </Border.Background>
                            </Border>
                            <ScrollViewer Margin="4,6,4,6"
                                                        SnapsToDevicePixels="False">
                                <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Once">
                                    <StackPanel.Resources>
                                        <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="#009DDB"/>
                                    </StackPanel.Resources>
                                </StackPanel>
                            </ScrollViewer>
                        </Grid>
                    </Popup>
                </Grid>
                    
            </ControlTemplate>
            </Setter.Value>
        </Setter>

    </Style>