Vertical Centering of DataGrid Cells

[OMGCHEN]

Bug explanation

When I set the RowHeight and configured VerticalAlignment for the cell style, why do extra border lines appear?

        <DataGrid Grid.Row="3" Grid.Column="1" Background="Transparent" 
                  ItemsSource="{Binding Group.AtQCList}"
                  Style="{StaticResource MaterialDesignDataGrid}"
                  AutoGenerateColumns="False"
                  IsReadOnly="True"
                  RowHeight="50"
                  md:DataGridAssist.SelectedCellBorderBrush="Transparent">
            <DataGrid.CellStyle>
                <Style TargetType="DataGridCell" BasedOn="{StaticResource MaterialDesignDataGridCell}">
                    <Setter Property="VerticalAlignment" Value="Center" />
                </Style>
            </DataGrid.CellStyle>
            <DataGrid.Columns>
                <DataGridTextColumn Header="Name" Binding="{Binding Name}">
                </DataGridTextColumn>
                <DataGridTextColumn Header="Mobile" Binding="{Binding Mobile}" />
            </DataGrid.Columns>
        </DataGrid>

If I leave VerticalAlignment as its default value Stretch, the display works fine, but the cell content cannot be vertically centered.

Version

5.3.0

[corvinsz]

@OMGCHEN thanks for your detailed bug report.
Those are redundant horizontal grid lines (GridLinesVisibility="Horizontal") of the datagrid.
This seems like a bug in the template.