The menu gets the focus off other components such as TextBox and NumericTextBox on every keystroke in the input area. 

I would expect that setting HasChildren to false would prevent sub-menus and expand arrows from the current item. It does not. I am using hierarchical data binding.

I don't see any examples with a menu item separator.  Is there a way to create a menu item separator?

If the collection you pass to the Menu Data parameter is null or empty, you will get an exception like this

System.ArgumentNullException: Value cannot be null. (Parameter 'source')
   at System.Linq.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at Telerik.Blazor.Components.TelerikMenu`1.<BuildRenderTree>b__0_0(RenderTreeBuilder __builder2)

I need to style the entire menu item, not just my template, but there are classes from the menu that I cannot override with my code or template.

 

Using the demo on https://demos.telerik.com/blazor-ui/menu/index if you select Item 1 with the left mouse button, both Item 1 and Item 2 drop downs open, see attached images