Code Server Nginx Ssl Error

An unexpected error occurred that requires a reload of this page.
The workbench failed to connect to the server (Error: WebSocket close with status code 1006)

Code server popped up a websocket error when I exposed code-server using a custom domain and a custom port via nginx.

Here is part of my nginx.conf.

  upstream code{
      server xxxxxxxxx;
  }
  server {
    listen 40032 ssl;
    server_name xxxxxxxx;
    ssl_certificate certs/mycert.pem;
    ssl_certificate_key certs/mykey.pem;
    ssl_ciphers HIGH:!aNULL:!MD5;
    charset utf-8;
    client_max_body_size 500M;
    location / {
        proxy_pass http://code;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $host;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_http_version 1.1;
        proxy_set_header Accept-Encoding gzip;
    }
  }

Websocket support has already been enabled by adding proxy_http_version 1.1 and proxy_set_header Upgrade $http_upgrade,
but this error is still being reported.

The key to the problem lies in the proxy_set_header Host $host; in the above configuration, after changing it to
proxy_set_header Host $http_host;, problem disappeared.

Here is the explanation:

https://stackoverflow.com/questions/15414810/whats-the-difference-of-host-and-http-host-in-nginx/76875724#76875724

Based on Nginx 1.18, code-server: v4.17.1