No, Jurgen. I do not have any additional definitions nor location definitions. I actually removed everything certbot-related and reinstalled the snap with the same effect. Whatever configuration was available I have provided it and I am happy to provide whatever else may be helpful to find out the cause.
The renewal does not work even if "standalone" module is selected and launched after Apache is stopped. As I understand it, "standalone" launches it's own webserver for verification:
**wojtek@hq** : **/** $ sudo certbot certonly --standalone -d hq.zajc.pl --dry-run
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator standalone, Installer None
Cert is due for renewal, auto-renewing...
Simulating renewal of an existing certificate for hq.zajc.pl
Performing the following challenges:
http-01 challenge for hq.zajc.pl
Waiting for verification...
Challenge failed for domain hq.zajc.pl
http-01 challenge for hq.zajc.pl
Cleaning up challenges
Some challenges have failed.
**IMPORTANT NOTES:**
- The following errors were reported by the server:
Domain: hq.zajc.pl
Type: unauthorized
Detail: Invalid response from http://hq.zajc.pl/.well-known/acme-challenge/eYpFCUrUN3eA7vPGkPEI3H_znrp-I8cOabnLo3utj6U
[91.216.30.50]: 404
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.
I don't know what you mean by "nonsense", however the page you linked redirects to owncloud login, and indeed the sentence "your system want's expired browsers" really makes no sense in English - I regretfully have no idea what you meant.
Yes, it is my system and I am trying to fix it. Came here for constructive "community support", not for patronizing.