Schedule block preview covers another zone.

Steps:
1. Create a new Landing Page with layout "1_2" (2 zones, left narrow, right wide).
2. Add one Schedule block to each zone. Templates Hero and List.
3. Set overflow from first zone to second.
4. Add content item 'Home/Blog/Why we love NYC' to first zone.
5. Add content items 'Home/Places & Tastes/Places/Valencia, Spain' & 'Home/Places & Tastes/Places/Kochin, India' to second zone. [see first screenshot]
6. Add content item 'Home/Places & Tastes/Places/Brooklyn, New York' to first zone.
7. Confirm push-out.
8. Examine the preview.
Issue: Preview from first zone covers part of the second zone. [see second screenshot]