DuckDNS/LetEncrypt: Invalid date on new, updated, valid certificate

When i navigate to my HA instance (https://xxx.duckdns.org:8123) i get an SSL error (“The date of the Home Assistant certificate is invalid”). Upon inspection of the certificate it appears that the certificate has expired:
Screenshot 2023-10-24 154827

However, the certificate seems to have been renewed, as per the DuckDNS log:

DuckDNS log:
# INFO: Using main config file /data/workdir/config
+ Account already registered!
[13:28:58] INFO: OK
xxx.xxx.xxx.xxx
NOCHANGE
[13:28:58] INFO: Renew certificate for domains: xxx.duckdns.org and aliases: 
 INFO: Using main config file /data/workdir/config
Processing xxx.duckdns.org
 + Checking domain name(s) of existing cert... unchanged.
 + Checking expire date of existing cert...
 + Valid till Nov 27 17:04:44 2023 GMT (Longer than 30 days). Skipping renew!

Both files in the /ssl/ folder (fullchain.pem and privkey.pem) have a timestamp of Aug 29 2023, 11:04, so the cert seems to have been renewed on August 29.

Here’s the DuckDNS config:

domains:
  - xxx.duckdns.org
token: xxx
aliases: []
lets_encrypt:
  accept_terms: true
  algo: secp384r1
  certfile: fullchain.pem
  keyfile: privkey.pem
seconds: 43200

and the configuration.yaml:


# Loads default set of integrations. Do not remove.
default_config:

# Text to speech
tts:
  - platform: google_translate

automation: !include automations.yaml
script: !include scripts.yaml
scene: !include scenes.yaml
homeassistant:
  packages: !include_dir_named packages
logger:
  default: warning
http:
  ssl_certificate: /ssl/fullchain.pem
  ssl_key: /ssl/privkey.pem

So there seems to be a discrepancy between the ssl certificate pulled by let’s encrypt and the one the browser sees? Any ideas why this might be the case?
thank you.

Check all your file paths.
DuckDNS config might be missing /ssl

And restart you host too to make sure the certificate is not locked somehow.