www.wysiwygwebbuilder.com

I'm not sure where the issue comes from with this.

On this page: https://www.isliphamlethistory.org/hist ... rkers.html

If you select the "About" menu, the dropdown appears, but the items from the menu below it bleed through.

In the layer priority, the entire masthead including the menubar has front priority and a solid gradient background.

The menu with the items that are bleeding through are much further back in the visibility priority.

This happens on various browsers and on mobile.

Any suggestions?

The reason for this is because the menu has a higher z-index than the header.

To solve this add the following code to the Page HTML:

Interesting. In the Object Manager, I had the masthead in front. I tried this override of the z position and it worked in preview, but not in publish, even with a refresh.

The masthead is a master page. I had embed as layer set in its object properties. When I unchecked that, it worked, even without the z order change.

I'm not sure I understand exactly why that is though.

There is not difference between preview and the published website,. In both cases the exact same HTML will be generated.
So, if you see a difference then either you did not publish all files or there is a browser cache issue.