Every second day a new surprise. Technology… :)
Yesterday: I figured out that my provider’s router had IPv6 problems and my IPv6 connections were, let’s call it ‘unstable’, or mostly not working at all.
Funny enough, a simple restart - have you tried to turn it off and on again? - fixed the problem.
Today: When I visited my own website, suddenly I got the caio (cloud-all-in-one) webinterface and thought - WTF?!
The puzzle was: Somehow I put nginx to listen on some of the subdomains on IPv6 and on some not, including the website behind the actual main domain. And as my home network was finally IPv6-able again, it of course used it, as it should be. And with this showed me also not my website anymore but the first accessible IPv6 configured domain it could find.
Despite not actually a dumb approach, still very confusing.
Fix is of course to set in all configured vhost domains listen [::]:443 ssl; below the usual listen 443 ssl; and all the magic works by itself… :D