Answer
Tailscale serves WebSocket upgrade on port 443 but fails due to **SSL/TLS protocol errors** because port 443 is typically reserved for HTTPS and requires a valid SSL certificate. If the certificate is missing or invalid, browsers reject the connection, leading to `ERRSSLPROTOCOLERROR`. On custom ports like 8443, the same configuration works because browsers are more lenient with SSL errors on non-standard ports. Ensure you're using a valid certificate for port 443 and that the backend WebSocket server is correctly handling the upgrade request.
4a602f4b-d347-4fb3-b9fe-ce39e50caedc
Tailscale serves WebSocket upgrade on port 443 but fails due to SSL/TLS protocol errors because port 443 is typically reserved for HTTPS and requires a valid SSL certificate. If the certificate is missing or invalid, browsers reject the connection, leading to ERRSSLPROTOCOLERROR. On custom ports like 8443, the same configuration works because browsers are more lenient with SSL errors on non-standard ports. Ensure you're using a valid certificate for port 443 and that the backend WebSocket server is correctly handling the upgrade request.