Sortable flicker when dragging portlets

Sortable flicker when dragging portlets

Hi there

I am using the portlets example from the JQuery sortable website.
We have set the tolerance to "pointer" as below:

    $( ".column" ).sortable({
      connectWith: ".column",
      handle: ".portlet-header",
      cancel: ".portlet-toggle",
      placeholder: "portlet-placeholder ui-corner-all",
      tolerance: "pointer"

When dragging a widget over another widget which is off the top off the page, the widget and page flickers very fast.

This issue happens in the Chrome browser (Version 62.0.3202.94 (64-bit))
The flicker is still there when tolerance is set to "intersect", but a lot less noticable.
Is there any scroll offset we need to add to stop this occurring?

Any help would be greatly appreciated?

(Video to recreate this issue is attached.)