It looks like your issue might stem from one of the following causes:

Possible Causes and Fixes:

1. Misconfiguration in Nginx Reverse Proxy

   • If Nginx is improperly handling WebSockets or HTTP requests, it could be modifying or breaking JSON responses from your Llama 2 API.
   • Fix: Ensure your Nginx configuration includes proper proxy settings:
     nginx

     CopyEdit

     location / {
     proxy_pass http://localhost:PORT; # Replace PORT with your Llama 2 API port
     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_buffering off;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "Upgrade";
}


2. Certbot HTTP-01 Challenge Interference

   • Certbot might have temporarily modified your Nginx config and is interfering with normal operation.
   • Fix: Try restarting Nginx after Certbot finishes:
     nginx

     CopyEdit

     sudo systemctl restart nginx


3. Mixed Content Issue (HTTP vs. HTTPS)

   • If the AI server is still using HTTP but Nginx is serving HTTPS, responses might be malformed.
   • Fix: Ensure the Llama 2 backend API is also running with HTTPS or use proxy_redirect:
     nginx

     CopyEdit

     proxy_redirect http:// https://;


4. JSON Response Encoding Issue

   • If Nginx is interfering with response headers, ensure JSON content-type is correctly set.
   • Fix: Add:
     nginx

     CopyEdit

     proxy_set_header Content-Type application/json;


Next Steps

• Check the Nginx logs:
  nginx

  CopyEdit

  sudo journalctl -u nginx --no-pager --lines=50

• Verify Certbot logs for potential misconfigurations:
  bash

  CopyEdit

  sudo cat /var/log/letsencrypt/letsencrypt.log

• Try disabling Nginx temporarily and directly accessing the AI server to confirm JSON responses are correct.