When using a large context menu that doesn't fit on the screen, a scrollbar is shown within the context menu. Unfortunately the scrollbar is not shown when the context menu contains multiple nesting levels.
Example https://dojo.telerik.com/uYUqazaP. This example shows a context menu with a single nesting level, which correctly displays a scrollbar. The other context menu contains 2 levels of nesting, which does NOT show the scrollbar.