One thing that you may notice is when you try to drop and element into the dd tab content area, it disappear. Simply hard refresh (ctrl+f5) the Weebly editor AFTER you dropped an element in the content area. Go back to your page and you should see the DD tab content area working properly again.
Some bugs usually appear after every Weebly major updates and will eventually go away. However, this may be a few days to a few months. Unfortunately, we can’t control Weebly’s platform so we can only work around its restriction.