Core WordPress Redirects – what is causing this?

I believe WordPress is generating some redirect rules and I have no idea where it’s coming from.

The given URL 301 redirects to a related post, presumably based on the URL.

I have tested this with a default theme, all plugins deactivated, Cloudflare turned off and the same result appears with an active 301 redirect.

What is causing this and how can I turn it off?

The page I need help with: [log in to see the link]