Drag the blue div over the target. The target background will not change to red. This means the mouseover event did not fire because the cursor is not over the DOM branch containing the target. The blue div is always under the cursor and prevents this event from firing.

If you mouseover the target without dragging the blue div then you will see the background change to red. Refresh the browser to play again.

donut dragdrop to solve this problem

draggable
target