The appearance problem can be seen on http://demos.telerik.com/aspnet-ajax/pivotgrid/examples/firstlook/defaultcs.aspx.
Click on the filter icon for Product name, you will find that the save and cancel buttons are off-screen. And if you hover over Label Filters or Value Filters the window is not wide enough to fit the popout menus that show:
Hi Folks,
The issue is fixed and will not exist in the upcoming in mid-June R2 2020 SP1 release.
Regards,
Rumen
Progress Telerik