I have a very similar issue and it is not the first time it happens to me. Last time it resolved without understanding how....
Access to my home server (FreeNAS accessed via NoIP redirect): cartan.hopto.org
Browser (Chrome) says Privacy Error: NET::ERR_CERT_DATE_INVALID
Details in Chrome shows:
Expires on: Dec 3, 2021
Current date: Dec 8, 2021
So I logged on to my server and ran letsencrypt which says:
Found the following certs:
Certificate Name: cartan.hopto.org
Expiry Date: 2022-03-07 20:36:05+00:00 (VALID: 89 days)
Certificate Path: /usr/local/etc/letsencrypt/live/cartan.hopto.org/fullchain.pem
Private Key Path: /usr/local/etc/letsencrypt/live/cartan.hopto.org/privkey.pem
I've searched all my server for a possible other certificate (find / -name *.pem) and found nothing.
I've cleared the cache of this browser and tried from other machines including from my phone disconnected from the wifi,.... still the same error...
Any idea ?
Thanks in advance,