Thanks, @NickA. I’ve seen that post, and similar ones, but I am not getting a No valid IP address error so think I have a different problem. Mine seems to be permission-related, or at least that’s my suspicion and as noted in a new question. (This thread was getting no attention after six days so I refined it and reposted.)
I’ve not changed anything about the Freedombox configuration, or my network, and up until the certificate expiration, everything has been working fine.