Can't update Let's Encrypt

Hello,
my Let’s Encrypt cert has expired and I wanted to renew it.
Unfortunately, I now get an error message and don’t know what the problem could be.
had it installed with certbot and so far everything has worked, now I get this error message:
(…)

Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator nginx, Installer nginx
Cert is due for renewal, auto-renewing...
Renewing an existing certificate for support.mydomain.de
Performing the following challenges:
http-01 challenge for support.mydomain.de
Waiting for verification...
Challenge failed for domain support.mydomain.de
http-01 challenge for support.mydomain.de
Cleaning up challenges
Some challenges have failed.

IMPORTANT NOTES:
 - The following errors were reported by the server:

   Domain: support.mydomain.de
   Type:   connection
   Detail: 80.xxx.xxx.xx: Fetching
   http://support.mydomain.de/.well-known/acme-challenge/wU_JunhBoEUTR56eYMhdHr-kqGvehXxxxxSPqGgxxxx:
   Timeout during connect (likely firewall problem)

   To fix these errors, please make sure that your domain name was
   entered correctly and the DNS A/AAAA record(s) for that domain
   contain(s) the right IP address. Additionally, please check that
   your computer has a publicly routable IP address and that no
   firewalls are preventing the server from communicating with the
   client. If you're using the webroot plugin, you should also verify
   that you are serving files from the webroot path you provided.

(…)

Firewall is open to Port 80 and 443 and pointing to the server IP.
DNS AAA is entered correctly and points to our correct public IP.

who could help me?

greeting

MZ

Still, you receive an timeout.
Make sure letsencrypt can reach the machine all the way.

If the machine is behind a firewall ensure port 80 is allowed for your destination and that the destinations firewall allows port 80 as well.

From outside can you telnet :80 to your IP and or DNS name?

Is there a service running on 80 that needs to be stopped for your renewal? Why isn’t auto-renew/cron configured?