Why does any hosting domain redirect to ispmanager page?

Question

Nginx

In general, it somehow happened that now when you try to open any domain name located in ispmanager, not the site of this domain opens, but the authorization page in ispmanager. Tell me, where should I fix it?
CentOS 6.5
ISPmanager-Pro 4.4.10.23

Answer 1

Specify DNS+Domain names in ISPmanager (specified?)
What operating system?

Answer 2

It looks like the built-in ihttpd is now listening instead of your webserver. Check if this is the case (your webserver is running, ihttpd is running) ps aux, see what port is listening (ihttpd listens on port 1500 by default, but who knows ;) netstat -ntlp. Fix the problem if found.

Answer 3

If all your domains open a web panel on your server, then the domains on the provider's side are configured correctly.
After someone types in a domain name in a browser, the request is redirected to your physical server, and then some Web server (apache, nginx, etc.), depending on the domain name and settings, shows/executes/redirects files/programs etc. from different folders.
Since you write in the comments that the student installed nginx, then most likely the source of the problem is an incorrectly installed nginx.
It is likely that nginx accepts all requests that come in on port 80, regardless of the domain name, and forwards them to the ISP.
In nginx, you need to create different settings for each domain name.
It will look something like this:

server {
    listen IP.XXX.XXX.XXX:80;
    server_name example.com; 
...
}

If, after the intervention of the student, apache is running on port 8080, you can try to open your domain in the browser examle.com:8080 and example.com:80 case, nginx is responsible. If apache opens pages correctly, and nginx does not open correctly, then you need to configure nginx.