Good morning,
I have mounted in my lab, several servers with different applications configured with port 80, in front of these servers I have a reverse proxy (nginx) that performs the redirections to the different servers. Being several different sites I have configured in the sites-avalable and sites-enabled a configuration file for each of the servers. Everything works fine if I have all the servers with the certificate configured, but I have noticed that if there is one that I have not configured with HTTPS if I force the connection by typing in the browser bar instead of telling me that no certificate is found, it tells me that the certificate does not correspond to the domain I want to access and redirects me to the https that I have configured in another file, in the next in alphabetical order.
That sounds like normal nginx behavior if I understand your situation correctly.
If nginx does not have a server block for the domain requested it uses the default server block for that port. The default is usually the first one unless you declare a different one.
For HTTPS requests, this can result in you getting an error about the cert not matching the name used for the request.
The nginx docs are the best place to learn how this works.
I think you mean it proxies to the different servers.
If so, then both HTTP and HTTPS are proxied.
Thus, when you try to reach a site that doesn't have a certificate, the proxy will match it to the default HTTPS vhost.
As stated, this is an unavoidable nginx [proxy] configuration issue.
