workaround:
public MainWindow()
{
    InitializeComponent();

    this.grid.Loaded += grid_Loaded;
}

void grid_Loaded(object sender, RoutedEventArgs e)
{
    this.grid.ChildrenOfType<Grid>().FirstOrDefault(x => x.Name == "PART_OuterGrid").RowDefinitions[1].Height = GridLength.Auto;

    var cells = this.grid.ChildrenOfType<GridViewHeaderCell>();
    foreach (GridViewHeaderCell cell in cells)
    {
        cell.ChildrenOfType<Grid>().FirstOrDefault(x => x.Name == "PART_OuterGrid").RowDefinitions[1].Height = GridLength.Auto;
    }
}

This happens in the following scenarios:

1. The FilterMemberPath points to the Date property of a DateTime one.
2. The column name contains "[]" square brackets.

When we make frozen column width bigger than the window will hide other columns. Scrolling is applied only to not frozen columns. So we can't scroll to see other columns.

A possible workaround is to set MaxWidth property of the column.

The issue is reproduced only when the items in the source collection have properties with duplicated values and they are sorted before the selection is processed. If the property values are unique or the SelectionMode is set to Multiple, the selection works as expected both with sorted and unsorted data. The workaround is to use either Multiple SelectionMode, or Cell/Mixed SelectionUnit.

For the time being, an appropriate converter should be used for the bindings.

Currently, if the value set to the RowHeight of RadGridView is lower than the Height of the highest cell(or the Height of a Hierarchy defined), it will not be respected. Provide an option the RowHeight to have greater weight than the height of the cell.

Add a TextAlignment property to the GridView's AggregateFunctions to set the alignment of the resulting text. 
Apply to both Caption and FormattedValue simultaneously. 
This way we won't have to make custom ItemTemplates for the AggregateResultsList in each footer, when using AggregateFunctions out-of-the-box.

In an application, I bind a DataTable with many rows to a RadGridView. As soon as, the datatable is binded, I see the memory needed by the application growing. The problem is that the binding is done each time the content of the DataTable is changing. It seems that the memory is never cleared and keep growing until a MemoryException is thrown. This does not appear with a WPF standard GridView. Do you know why ?

In Office2016 when we increase the DPI of the Windows a left border in the header of column disappears. As a workaround you can set the Width property of all columns.

Current workaround for the affected themes - Define the following control template for the GridViewCheckBox:

			<ControlTemplate x:Key="GridViewCheckBoxTemplate" TargetType="telerik:GridViewCheckBox">
				<Grid HorizontalAlignment="Left" VerticalAlignment="Center" Width="13" Height="13">
					<VisualStateManager.VisualStateGroups>
						<VisualStateGroup x:Name="CheckStates">
							<VisualState x:Name="Checked">
								<Storyboard>
									<ObjectAnimationUsingKeyFrames BeginTime="0" Duration="0" Storyboard.TargetName="CheckedPath" Storyboard.TargetProperty="(UIElement.Visibility)">
										<DiscreteObjectKeyFrame KeyTime="0">
											<DiscreteObjectKeyFrame.Value>
												<Visibility>Visible</Visibility>
											</DiscreteObjectKeyFrame.Value>
										</DiscreteObjectKeyFrame>
									</ObjectAnimationUsingKeyFrames>
								</Storyboard>
							</VisualState>
							<VisualState x:Name="Unchecked"/>
							<VisualState x:Name="Indeterminate">
								<Storyboard>
									<ObjectAnimationUsingKeyFrames BeginTime="0" Duration="0" Storyboard.TargetName="IndeterminatePath" Storyboard.TargetProperty="(UIElement.Visibility)">
										<DiscreteObjectKeyFrame KeyTime="0">
											<DiscreteObjectKeyFrame.Value>
												<Visibility>Visible</Visibility>
											</DiscreteObjectKeyFrame.Value>
										</DiscreteObjectKeyFrame>
									</ObjectAnimationUsingKeyFrames>
								</Storyboard>
							</VisualState>
						</VisualStateGroup>
					</VisualStateManager.VisualStateGroups>
					<Grid Background="Transparent">
						<Border
                        BorderBrush="{TemplateBinding BorderBrush}"
                        Background="{TemplateBinding Background}"
                        BorderThickness="{TemplateBinding BorderThickness}"
                        CornerRadius="{telerik:Office2016Resource ResourceKey=CornerRadius}"/>
						<Border x:Name="IndeterminatePath"
                        Width="9"
                        Height="9"
                        VerticalAlignment="Center"
                        HorizontalAlignment="Center"
                        Background="{telerik:Office2016Resource ResourceKey=IconBrush}"
                        Visibility="Collapsed"/>
						<TextBlock x:Name="CheckedPath"
                        HorizontalAlignment="Center"
                        VerticalAlignment="Center"
                        FontSize="13"
                        FontWeight="Normal"
                        FontStyle="Normal"
                        Foreground="{TemplateBinding Foreground}"
                        FontFamily="{StaticResource TelerikWebUI}"
                        telerik:GlyphAdorner.ShowGlyphInDesignTime="True"
                        Opacity="1"
                        Margin="-1 0 0 0"
                        Visibility="Collapsed">
                    <Run Text="{StaticResource GlyphCheck}"/>
						</TextBlock>
					</Grid>
				</Grid>
			</ControlTemplate>
			<Style  TargetType="telerik:GridViewCheckBox" BasedOn="{StaticResource GridViewCheckBoxStyle}">
				<Setter Property="Template" Value="{StaticResource GridViewCheckBoxTemplate}"/>
			</Style>

Fix available in LIB version 2017.2.814.

Available in LIB version: 2017.2.724

Available in LIB version: 2017.2.710

Available in LIB version: 2017.2.703

I am setting the status of the item to Declined as the reported behavior is due to the fact that the RowDetailsVisibilityMode is set to VisibleWhenSelected. The default behavior of RadGridView is to split the merged cell when a row with expanded row details is added. Thus, the reported issue you are is the expected one. If setting the RowDetailsVisibilityMode is removed the control will behave as expected.