SyncPlay Fails

[xtendo]

Try removing the location block for the /jellyfin/socket route as you've already configured the WebSocket support for all routes. If it then still doesn't work I merged your config with mine so try and see if that solves it.

Code:

location /jellyfin {
    # This proxy pass to the HTTP port is correct based on our tests.
    proxy_pass http://127.0.0.1:8096;
    proxy_set_header Host $host;

    # These headers tell Jellyfin it is behind a proxy.
    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_set_header X-Forwarded-Protocol $scheme;
    proxy_set_header X-Forwarded-Host $http_host;
    proxy_set_header X-Forwarded-Ssl on;

    # WebSocket headers (also included here for general compatibility)
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";

    proxy_redirect off;
    proxy_buffering off;
    proxy_cache off;
}

I have just replaced my entire location /jellyfin block with the exact one you suggested, including the additional X-Forwarded-Host , X-Forwarded-Protocol , and proxy_cache off directives. Unfortunately, after restarting Nginx and performing a hard refresh, the result is exactly the same. The main Jellyfin UI works perfectly, but clicking to join a SyncPlay group is still unresponsive.

I really appreciate you taking the time to help me diagnose this. Thank you again for your expertise.