Let's Encrypt renewal not working
short description
We noticed that the renewal of Let's Encrypt certificates is not working as expected, on several servers. The certificates are not renewed - after unchecking and activating the Let's Encrypt checkbox in ispconfig the certificate gets renewed again.
We install cerbot by downloading it from the official site and running it once (to install all necessary packages and so on). Some servers have older and some newer versions of certbot, but all of them do have the same issue with renewal.
How can I check if or when ispconfig is trying to renew Let's Encrypt certificates? I assume this might help identifing the cause.
correct behaviour
Renewing the Let's Encrypt certificates on time without manual actions.
environment
Server OS: Ubuntu Server OS version: 16.04 ISPConfig version: 3.1.13p