[Solved] Failure renewing certs with certbot behind reverse proxy

[JuergenAuer]

@cmonty14

Adding parameter --preferred-challenges http-01 looks like to be the key driver for the solution.
This means domain mail.biszumbitterenen.de was renewed successfully.

Yep, that worked. But now you have created 4 certificates with this domain name, 3 yesterday, one today.

https://transparencyreport.google.com/https/certificates?cert_search_auth=&cert_search_cert=&cert_search=include_expired:false;include_subdomains:false;domain:mail.biszumbitterenen.de&lu=cert_search

So if you test this two times again, the second time you fail hitting the 5 certificates per domain name set per week - limit.

Same with pve.biszumbitterenen.de

https://transparencyreport.google.com/https/certificates?cert_search_auth=&cert_search_cert=&cert_search=include_expired:false;include_subdomains:false;domain:pve.biszumbitterenen.de&lu=cert_search

Perhaps you may use --stage as option, so you use the test system (with own and higher limits).