problems on lists.freebsd.org error 503 backend fetch failed

Hi, if there's a better place to report this then please advise

It seems the web-mail-list software for FreeBSD has failed partially (mostly?)

For example, these work, to display the subjects of messages
https://lists.freebsd.org/pipermail/freebsd-ports/2018-September/thread.html
https://lists.freebsd.org/pipermail/freebsd-ports/2018-August/thread.html

but clicking on most of them throws this error:
Error 503 Backend fetch failed

Backend status: Backend fetch failed

These won't even show the message list:
https://lists.freebsd.org/pipermail/freebsd-ports/2018-July/thread.html
https://lists.freebsd.org/pipermail/freebsd-ports/2018-June/thread.html

full error is: 
Error 503 Backend fetch failed

Backend status: Backend fetch failed

Transaction ID: 476875217 (always varies)

Other lists similarly fail. Maybe linked to the mailman problem reported earlier?

thanks,
-- 
J.