So as title says i found kinda an issue and i am not sure is this some sort of a bug in ISPConfig or something is wrong server side specifically. I have the standard scenario following one of the "The Perfect Server" guides for web hosting having multiple clients and multiple websites setup on server all through ISPConfig but i just found out i don't know if this is a bug server side or something with ISPConfig or Let's Encrypt. I have Client1 > bwebsite.com Client2 > awebsite.com Client3 > cwebsite.com etc The issue happens if i go to domain edit and disable ssl and let's encrypt on cwebsite.com, the server no longer point to that domain, instead it redirects to awebsite.com, actually it redirects to first alphabetical domain name in domain list and this will happen unless i enable back let's encrypt or go to ftp and delete let'sencrypt shotrlinks created in domain ssl. A strange thing this is, but could be installation specific to my server or something don't get properly updated through ispconfig.
This is normal, see this feature request: https://git.ispconfig.org/ispconfig/ispconfig3/-/issues/5143 What I usually do on my systems is create a website 000.companyname.com, so that will be the default config until this is implemented.
I wasn't aware this is long time issue, however i never had a need to remove let'sEncrypt from domain until now. Looks like i will do a workaround as suggested in the tread as you said. To make a default website to fall back to it.
That's actually not an issue, it's the default behavior of apache and Nginx web server. But some people don't like how apache and Nginx handle this, that's why they made a feature request.