Hi Anne,
It doesn't make sense regardless of when I make a video screencapture. You will know what I mean if you recreate it. Please create a complex menu items with multiple level 2 items. View the menu items in HelixUltimate Mega Menu and note how the listing looks like. Now, create another level 1 menu item them batch move those level 2 menu items to the newly created level 1 menu item. Go back to the helixultimate megamenu and see how is the listing.
In my setup, the level 2 menu items in the previous level 1 mega menu is still listing the level menu items which I already moved to another level 1 menu item.