Creating a strip (top bar style) above a merged header, results in spacing issue

Hello team,

I'm wanting to create a basic customer message above the header BUT when I try to do this adding a new hook BEFORE_HEADER on a design with a merged header I get issues where the content from this new element is eating into the merged header. This doesn't affect things too badly on the desktop view but on small screens the header is then overlapping the page content.

It's quite hard to explain so I've included admin details so you can see the issue directly. I'm sure it will make perfect sense once you see it.

Thanks in advance for your assistance.