See this Screencast for a short video of the issue at runtime: https://www.screencast.com/t/YXm6xOtO 

Here's the code to reproduce: 

<grid:RadDataGrid ItemsSource="{x:Bind ViewModel.DataItems, Mode=OneWay}"
                  UserGroupMode="Disabled"
                  UserFilterMode="Disabled"
                  UserColumnReorderMode="None"
                  UserSortMode="None"
                  AutoGenerateColumns="False"
                  GridLinesVisibility="Horizontal">
    <grid:RadDataGrid.Columns>
        <grid:DataGridNumericalColumn Header="1"
                                      PropertyName="Key"
                                      SizeMode="Auto" />
        <grid:DataGridTextColumn Header="2"
                                 PropertyName="First"
                                 SizeMode="Auto" />
        <grid:DataGridTextColumn Header="3"
                                 PropertyName="Second"
                                 SizeMode="Auto" />
        <grid:DataGridTextColumn Header="Stretchy"
                                 PropertyName="Stretch"
                                 SizeMode="Auto" />
        <grid:DataGridTextColumn Header="5"
                                 PropertyName="SecondLast"
                                 SizeMode="Auto" />
        <grid:DataGridTextColumn Header="6"
                                 PropertyName="Last"
                                 SizeMode="Auto" />
        <grid:DataGridNumericalColumn Header="7"
                                      PropertyName="Count"
                                      SizeMode="Auto" />
    </grid:RadDataGrid.Columns>
</grid:RadDataGrid>

See this forum thread for reproducible and workaround: http://www.telerik.com/community/forums/legend-will-only-display-labels-(windows-10)

Available in the R2 2018 release.

The uwp radlistview vertical scrollbar disappears when focus is lost -
I think I need something like 
https://www.telerik.com/forums/listview-width-with-or-without-vertical-scrollbar
 <telerik:RadListView.Commands. ListElement.Scroller.Scrollbar.FillElement.Visibility

But I may be missing something?

Would be great if the TimeBar from WPF would be added to the UWP family. No new features required as the WPF equivalent is rich enough. Just port as is!

Testing the Telerik RadialMenu control in the UWP app ,  when you click on the radialmenu the control flickers for the mouseclick event on desktop.  plse consider changing the "flicker" to something more like a keypress , a image blur or something else. Or slow down the flicker considerable , your effect looks more like a defect of image rendering at the moment. 

EDIT, Cancel and Save strings cannot be localized through LocalizationManager.

Available in the R2 2018 release.

Enabled the control to load its ExpandableContent using the x:DeferLoadStrategy="Lazy" attribute.

Using Textbox in CellTemplate with UpdateSourceTrigger=PropertyChanged result in caret position jumps to beginning and thus the date recorded is reversed e.g. 321 instead 123.