Hi,
from your descriptions, I would say that this is actually the same issue as the one mentioned here: SOLVED: Copy Paste full page creates artifact doms - but possibly with different steps to reproduce it.
We are working on a solution, that will notify you if the elements like this exists, and you will be able to remove it. We also identified a few options, how this element could be generated and we fixed them.
To fix the issue, you can copy-paste all top-section elements individually (not with copy-all), and the issue should be gone.
But, if you can update the website to the 2.0 beta (on staging!), then I suggest that you enable “Orphaned element checker” here: Bricks 2.0-beta Changelog – Bricks, and try to save the page you have issues with.
Let me know if that fixes the issue.
Thanks,
Matej