If we enable grouping on a grid which has `FilterMode="Telerik.Blazor.FilterMode.FilterRow"` then we can no longer successfully get focus into any of the filter row edit controls.

Clicking on filter text input box (I think you need to do it a few times) causes a js error and does not put the text input focus into the filter text input.

JS exception is:

telerik-blazor.js:35 Uncaught TypeError: Cannot read property 'getAttribute' of null

    at t.value (telerik-blazor.js:35)
    at Object.onDraggableDrag [as drag] (telerik-blazor.js:35)
    at e.value (telerik-blazor.js:35)
    at e.value (telerik-blazor.js:35)
    at e.value (telerik-blazor.js:35)
    at o.onDrag (telerik-blazor.js:35)
    at h._dragHandler (telerik-blazor.js:35)
    at HTMLDocument._pointermove (telerik-blazor.js:35)