Page with category layout not working

I have a pretty dumb support question.

I have a layout under themes/.../layouts/about/single.html.
I have a page under content/about/

I expected the page to use the layout under about/single.html, but instead it is using the default.
Is there something more that I have to do?
And is there a better way to do static pages with custom layouts?

Thank you!

I set the type and layout in the frontmatter to both be “about” and renamed the single.html to be about.html and this solved my issue.

Best to follow the guide laid out here: