I can confirm it still happens on preview, though I couldn't get it to happen after export. Even on preview though, it's less pronounced than it was, but it's still there, though getting it to happen is different.
The exported version above shows it not happening. Open the .capx, preview, click and drag from the layout area up to chrome's address bar, then let go. The black background should now be blue. Press and hold a direction arrow. Without letting go of it, perform the same action with the mouse, clicking the layout and dragging it to the address bar, and before letting go of the mouse, let go of the direction arrow. The square will keep moving.
I got it to happen once without 'selecting' the page first, but I don't know how.