NGINX reverse proxy with port - port is being lost

Question

I am trying to reverse proxy from an IPv4 listen to an IPv6 host all using port 8006.

The problem is the port number is getting lost, when it gets to the destination the :8006 is missing.

The .conf file

server { listen 8006 ssl;

    server_name gggggg.nnnnnn.com;
ssl_certificate /home/gggg-nnnn-com/pmg-api.pem;
ssl_certificate_key /home/gggg-nnnn-com/pmg-api.pem;

location / {
   proxy_set_header Host $http_host;
   proxy_set_header X-Real-IP $remote_addr;
   proxy_set_header X-Forward-For $proxy_add_x_forwarded_for;
   proxy_set_header Xforwarded_Proto $scheme;
   proxy_pass https://ggggg6.nnnnn.com:8006/;
}

}

Note: here are a few things I have tried but did not work:

       proxy_redirect off;
       proxy_redirect https://ggggg6.nnnnn.com:8006/;
   proxy_redirect default;
   proxy_redirect ~^(https?://[^:]+):\d+(?<relpath>/.+)$ https://ggggg6.nnnnn.com:8006$relpath;