ERR_CERT_COMMON_NAME_INVALID on chrome based browsers

When trying to login to my website (pvapp.umwelt-campus.de/user/loghin) on Chrome based browsers I get the error:

POST https://143.93.46.35:60702/user/login net::ERR_CERT_COMMON_NAME_INVALID

that's the IP and port of my backend.

On firefox it works fine, tho. I installed certificates by certbot. My corresponding nginx settings look like:

server {
        listen 80;
        server_name pvapp.umwelt-campus.de;
        return 302 https://$server_name$request_uri;
}

server{
        # SSL configuration
        listen 443 ssl default_server;
        listen [::]:443 ssl default_server;
        add_header 'Access-Control-Allow-Origin' '*';
        add_header 'Access-Control-Allow-Credentials' 'true';
        add_header 'Access-Control-Allow-Headers' 'Authorization,Accept,Origin,DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';
        add_header 'Access-Control-Allow-Methods' 'GET,POST,OPTIONS,PUT,DELETE,PATCH';

        ssl_certificate     /etc/letsencrypt/live/pvapp.umwelt-campus.de/cert.pem;
        ssl_certificate_key /etc/letsencrypt/live/pvapp.umwelt-campus.de/privkey.pem;
        ...

I also added https at my backend (running at https://143.93.46.35:60702) like:

https.createServer({
    key: fs.readFileSync('/etc/letsencrypt/live/pvapp.umwelt-campus.de/privkey.pem', 'utf8'),
    cert: fs.readFileSync('/etc/letsencrypt/live/pvapp.umwelt-campus.de/cert.pem', 'utf8')
  }, app)
  .listen(nconf.get('port'), function() {
    console.log(`App listening on port ${nconf.get('port')}! Go to https://143.93.46.35:${nconf.get('port')}/`)
  });

Already tried to clear cache, clear windows ssl-cache restarted everything and renewed the certs. Hope anyone has an idea. :)

Do I maybe need an extra cert for the backend?

Using Ubuntu 16.04.7 xenial (I know it's outdated)

Solution 1:

According to your comments in your now deleted previous question on this you have a different host that handles the login:

it's the login that's not working and giving the cert error. The frontpage is working fine.

You need either a certificate that contains both hostnames as SANs (Subject Alternate Name) or a different valid certificate for the second host.