ListBoxEdit - A selected item is unselected when its internal DateEdit is edited

Hello,
This behavior occurs because ListBoxEdit additionally handles the PropertyChanged event when you edit an item using DateEdit and refreshes items. To avoid this issue and achieve the same behavior as in the standard ListBox control, set ListBoxEdit's AllowLiveDataShaping property to "False":

XAML
<dxe:ListBoxEdit ItemsSource="{Binding Items}"
                    HorizontalContentAlignment="Stretch"
                    AllowLiveDataShaping="False">
    <dxe:ListBoxEdit.ItemTemplate>
        <DataTemplate>
            <dxlc:LayoutControl>
                <dxlc:LayoutGroup Orientation="Horizontal">
                    <dxlc:LayoutItem Label="supplierGroup">
                        <TextBlock Text="{Binding Lieferantengruppe}" />
                    </dxlc:LayoutItem>
                    <dxlc:LayoutItem Label="bis">
                        <dxe:DateEdit EditValue="{Binding bis}" />
                    </dxlc:LayoutItem>
                    <dxlc:LayoutItem Label="eyo">
                        <dxe:DateEdit EditValue="{Binding von}" />
                    </dxlc:LayoutItem>
                </dxlc:LayoutGroup>
            </dxlc:LayoutControl>
        </DataTemplate>
    </dxe:ListBoxEdit.ItemTemplate>
</dxe:ListBoxEdit>

Please try this approach and provide us with your results.

Thanks,
Kirill