I am trying to get this all to work nicely together and struggling greatly…

Basically, what I am trying to accomplish is this:

On the proxy server, port 83 is a simple index.html hosted page which contains an iframe. The iframe is attempting to open port 93 on the same server (the proxy server). Port 93 is a reverse proxy (Nginx) which is changing the user-agent and then executing a proxy_pass to the final web app (the one that I actually want to display). The final web app is located on a different server. I have been fussing with this for weeks. I have been able to make varying degrees of progress but I have to throw in the towel. I’m out of ideas. I have had this working before but I cannot recall what I did. Any thoughts?

Simplified ports and process: 10.10.10.100:83 (iframe) –> 10.10.10.100:93 (reverse proxy redirect with change in user-agent) –> 10.10.10.200:83

Port 83 (simple index.html supporting the execution of an iframe being ran on Nginx):

Conf from sites-enabled

server ｛
  listen 83 default_ server;
  listen [::]:83 default_server;
  root /var/www/test:
  index index.html
  server_name localhost;
  location / {
    try_files Suri Suri/ =404;
  ｝
}

Content of index.html

<style>
  #scaled-frame｛
    position=absolute;
    top: 0; left: 0;
    bottom: 0;
    right: 0;
    width:100%;
    height: 100%;
    border=none;
    margin=0;
    padding=0;
    overflow:hidden;
    z-index: 999999;
    zoom: 1;
    -moz-transform: scale （4）；
    -moz-transform-origin: 0 0i
    -o-transform: scale (4);
    -o-transform-origin: 0 0;
    -webkit-transform: scale （4）i
    -webkit-transform-origin: 0 0i
  }
</style>
<div>＜iframe id="scaled-frame" src="https://10.10.10.100:93">/iframe>
</div>

Port 93 (Nginx reverse proxy) – just a .conf file in sites-enabled
`

server
  {
    listen 93 default_server;
    location / {
       proxy_set_header User-Agent"Mozi11a/4.0（compatible; MSIE 6.0；Windows NT 5.1； Windows Phone 6.5.3.5）"；
       proxy_set_header Viewport "width=device-width, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no";
       proxy_connect_timeout 159s;
       proxy_send_timeout 600;
       proxy_read_timeout 600; 
       proxy_buffer_size 64k;
       proxy_buffers 16 32k; 
       proxy_busy_buffers_size 64k;
       proxy_temp_file_write_size 64k冫
       proxy_pass_header Set-Cookie;
       proxy_redirect off;
       proxy_hide_header Vary;
       proxy_set_header Accept-Encoding '';
       proxy_ignore_headers Cache-Control Expires;
       proxy_headers_hash_max_size 512;
       proxy_set_header Host $host;
       proxy_set_header Cookie $http_cookie;
       proxy_set_header X-Real-IP $remote_addr;
       proxy_set_header X-Forwarded-Host $host;
       proxy_set_header X-Forwarded-Server $host;
       proxy_set_header X-Forwarded-For $proxy_add_x_forwarded
       proxy_pass http://10.10.10.200:83/app/;
  }
}

`