The "Drop here" frame does not appear for empty zone.

Steps:
1. Create a new LP with at least 2 zones (or use existing but delete all blocks from zone).
2. Add a Schedule block to one of the zones.
3. Choose layout "List" and add a content item.
4. Try dragging the block from first zone to (empty) second.
Actual: The "Drop here" frame does not appear when mouse pointer is in the area of the second zone [screen1] (actually it appears only when the pointer is placed below half of the height of the zone [screen2]).
Expected: The "Drop here" frame does appear when mouse pointer is wherever in the area of the zone.

Remarks: Please see attached.