Node.js Digitalocean Ubuntu NGINX net::ERR_CONNECTION_TIMED_OUT what could be the problem?

Question

Nginx

Application on MEAN2-stack throws an error:

GET https://xx.xx.xx.xx:3000/api/check-email?email=tes... net::ERR_CONNECTION_TIMED_OUT

Also request:

curl https://xx.xx.xx.xx:3000/api/check-email?email=tes...

gives an error message:

curl: (35) gnutls_handshake() failed: An unexpected TLS packet was received.

Although the same request that starts with http will work fine:

curl xx.xx.xx.xx:3000/api/[email protected]

Everything works fine on the local server, but problems start on the production server.
Websockets are not used.
Base Url on frontend: ip and port on nodejs:
private baseUrl = 'https://xx.xx.xx.xx:3000/api/';

...
app.use( '/api', routesApi );
...
app.listen( 3000, 'xx.xx.xx.xx', () => {
  console.log( 'Server is running' );
} );

My nginx settings:

server {

    server_name helperra.com www.helperra.com;

    location / {
        root   /helperra/client/dist;
        try_files $uri $uri/ @node;
    }

    location @node {

        proxy_pass http://xx.xx.xx.xx:3000;
        proxy_redirect off;

        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }

    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/helperra.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/helperra.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
}
server {
    if ($host = www.helperra.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot

    if ($host = helperra.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot

    listen 80;

    server_name helperra.com www.helperra.com;
    return 404; # managed by Certbot
}

This is my first time setting up a server on Ubuntu and my first time dealing with nginx.

Answer 1

After I removed the host on the front and back, everything worked.

app.listen( port, () => {
  console.log( 'Server is running' );
} );

I spent two days to understand once again - it's better not to hardcode!

Answer 2

look at the nginx logs, apparently it doesn’t reach the upstream proxy, httP is in the same place, and you redirect everything to httpS