[MM3-users] /hyperkitty/list/ shows "example.com" / mailman3 archives not updated

/hyperkitty/list/ shows "example.com". Not the actual domain name that I configured. How can I fix this?

I would not mind too much about hyperkitty showing "example.com". But the more important issue is that mailman3 archives are not updated. Therefore I guess it's a symptom of a more important issue. E-mails to the list are delivered to e-mail subscribers, though. Seems only the web part is broken.

Using Debian buster mailman3 packages. In configuration folder /etc/mailman3 I cannot find any textual string saying "example.com". (grep -r -i example /etc/mailman3) Therefore I don't know where mailman3 gets "example.com" from.

Could be broken linux file/folder access rights? Any way to debug?

Kind regards, Patrick