In Odoo, there isn't a direct CORS (Cross-Origin Resource Sharing) option available within the CDN settings, even in Developer Mode. CORS is typically managed at the server or proxy level, not directly within Odoo’s settings. Here are a few steps to troubleshoot or manage CORS:

1. Configure CORS on Your Web Server:
   If you're using a CDN like Cloudflare or your server (e.g., Nginx or Apache), you need to configure CORS headers directly on the server. This can be done by editing the web server configuration to allow the necessary origins.
2. Using a Reverse Proxy:
   If you're running Odoo behind a reverse proxy (e.g., Nginx), you can set CORS headers there. Add the necessary Access-Control-Allow-Origin headers in your Nginx/Apache config.