List of steps to reproduce (step by step, including full links if applicable):
Cannot be consistently reproduced. I saw it twice for two different articles in the last 4 hours on fawiki. Latest occurrence was on this article. It gets resolved with page refresh.
What happens?:
The page's header appears after the page's menu.
What should have happened instead?:
Other information:
I took a screenshot of the HTML source of the page, and the <h1> tag is indeed placed before the <div> tag for the menu:
The bug doesn't seem to be at the HTML level; maybe it is at the CSS level? Or maybe it is browser-specific? I saw this on Firefox 101.