Unexpected intermittent 404s from Pages site

This is behaviour that I've just experienced right now, but this is not the first time I've experienced it. It seems worth of a bug report.

I've been browsing this GitLab Pages site: https://gitlab-com.gitlab.io/gl-infra/tamland/ci-runners.html

The accesses are logged correctly from my IP.

https://log.gprd.gitlab.net/goto/0cbfaa1bae71415cdc443ed1a61ae6f3

At some point, I clicked through to a new page and received a 404.

1. No deployment took place while I received the 404
2. After a few minutes of refreshing, the page returned.
3. No errors or 404s were logged in the ELK logs
4. This behaviour is consistent with the behaviour I've seen previously.
5. The problem appears to affect multiple pages that otherwise exist, not a single page.