ISPConfig Multi-Server - Let's Encrypt does not generate certificates for websites hosted on the sec

Hello everyone,

I'm experiencing an issue with an ISPConfig Multi-Server setup and, despite running several tests, I haven't been able to identify the root cause.

Environment

• ISPConfig 3.3.1p1
• Ubuntu 22.04
• Multi-Server setup
• mail01 (Master)
• web01 (Web Server)

Problem
When I enable the following options in ISPConfig:

• SSL
• Let's Encrypt

and save the website, the certificate is not generated.

In the database, the following values remain unchanged:
ssl = n
ssl_letsencrypt = n

In other words, it seems that ISPConfig never actually enables SSL for the website.

Synchronization
The web server receives all changes correctly.
In the sys_datalog table, the entries show:
server_id = 2
status = ok

So, from what I can see, synchronization between the master server and the web server is working correctly.

I followed the official ISPConfig Multi-Server installation guide exactly as documented (pages 1 and 2) available at the link below. The installation completed successfully, and the multi-server environment appears to be working correctly, except for the Let's Encrypt certificate generation on websites hosted on the secondary web server.

> link website "ISPConfig Perfect Multiserver setup on Ubuntu 24.04 and Debian 12"