I have a DataGrid and a DataGridTemplateColumn in the DataGrid. I set the CellTemplate of the DataGridTemplateColumn by a ComboBox. When I set the DataGridTemplateColumn visibility to Collapse, the Combo Box selection will be set to null. The issue occurs when I replace ComboBox by ListBox with multi selection mode.

Here is my XAML codes:

  <UserControl.Resources>
    <behaviors:BindingProxy x:Key="DataContextProxy" Data="{Binding}" />

  </UserControl.Resources>

 <DataGrid Grid.Row="1" x:Name="DataGrid"
              Style="{StaticResource HorizontalDatGridStyle}"
              AutoGenerateColumns="False"
              CanUserAddRows="False"
              ItemsSource="{Binding Overlaps}">
      <DataGrid.ColumnHeaderStyle>
        <Style TargetType="DataGridColumnHeader"
               BasedOn="{StaticResource HorizontalDataGridColumnHeaderStyle}">
          <EventSetter Event="Click"
                       Handler="DataGridColumnHeader_OnClick" />
        </Style>
      </DataGrid.ColumnHeaderStyle>

      <DataGrid.Columns>

       <DataGridTemplateColumn Header="Parents"
                                Visibility="{Binding Data.VisibilityModel.IsParents, Source={StaticResource DataContextProxy}, Converter={converters:BooleanToVisibilityGoneConverter}}">
          <DataGridTemplateColumn.CellTemplate>
            <DataTemplate>
              <ComboBox
                VerticalAlignment="Center"
                ItemsSource="{Binding Parents, Mode=OneTime}"
                SelectedItem="{Binding Parent}">
              </ComboBox>
            </DataTemplate>
          </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
<DataGrid.Columns>
</DataGrid>

I attempted to change visibility to Hidden instead of Collapse, but the issue hasn’t resolved.