proxy_http_version set to 1.1

proxy-http-version.conf

server {
  listen 80 default;
  server_name your_server.org;
  
  location / {
    proxy_http_version 1.1; # this is essential for chunked responses to work
    
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    
    proxy_pass http://localhost:9000;
  }
}