Last email not showing up in "Whole thread" view?

Hi all,

I wanted to report a transient error that I can't reproduce now, in
case there's some caching bug lying dormant somewhere. I visited

https://commitfest.postgresql.org/38/3668/

and the Latest email timestamp was 2022-07-25 11:12:00. But when I
clicked on the thread link, which is

https://www.postgresql.org/message-id/flat/CAHg+QDcVUss6ocOmbLbV5f4YeGLhOCt+1x2yLNfG2H_eDwU8tw(at)mail(dot)gmail(dot)com

the last email that showed up was sent in April, and the July email
was nowhere to be seen. If I then clicked the "Whole thread" link
again, it took me to

https://www.postgresql.org/message-id/flat/CAHg%2BQDcVUss6ocOmbLbV5f4YeGLhOCt%2B1x2yLNfG2H_eDwU8tw%40mail.gmail.com

(note the percent-escaping) and then I could see the July email. This
persisted for a few tries while I wrote this message... and then the
bug disappeared and I can now see the July email from both URLs.

I know debugging stale caches is "fun"... sorry I don't have much more
info. Is this a known problem?

--Jacob