I've been searching but didnt found anything usefull. I have several sites in my ISPConfig3.1. Some with SSL and some without SSL. If I try to enter with SSL in a not enabled SSL site, it redirects to a random enabled SSL site. For example: domain1.com is SSL domain2.com is SSL domain3.com is not SSL If I do https://domain3.com, instead of not viewing any site, It shows domain1 or domain2 ssl site.
Yes, that's the normal behaviour of the apache and nginx server. They show the first site in alphabetical order if there is no matching ssl site. If you want to show a default vhost, then enable the system ssl default vhost or create a site with a domaon name that is always first in alphabet like 000default.tld
When you select an IP in a website, then this ip needs its own default vhost in apache as a matching ip with wrong domain is still a stronger match than the default vhost for apache.