The nginx cache for https://core.trac.wordpress.org/ticket/54504 appears to be stuck in an updating state, with 2-day stale content being served.
This isn’t critical, but a sign of an nginxNGINX NGINX is open source software for web serving, reverse proxying, caching, load balancing, media streaming, and more. It started out as a web server designed for maximum performance and stability. In addition to its HTTP server capabilities, NGINX can also function as a proxy server for email (IMAP, POP3, and SMTP) and a reverse proxy and load balancer for HTTP, TCP, and UDP servers. https://www.nginx.com/. configuration change being needed I guess, or TracTrac Trac is the place where contributors create issues for bugs or feature requests much like GitHub.https://core.trac.wordpress.org/. is crashing on an unauthenticated request to that specific ticket consistently which seems unlikely.
$ curl -Is https://core.trac.wordpress.org/ticket/54504 | grep x-nc x-nc: UPDATING
In the above example, Comments 94-96 are not visible in the cached response (ie. a logged out incognito request), but are for an authenticated user.
Unknown if this affects many URLs, low priority as it seems likely a rare occurence.