Is the 'Origin is unreachable' (523) error on Android related to SSL/TLS certificates?

Yes, problems with SSL/TLS certificates can trigger this error. If the certificate is invalid, expired, or doesn't match the website's domain, your device might refuse to connect. Ensure your device's date and time are correct, as incorrect settings can cause certificate validation failures. Also, try clearing SSL state in your browser settings (though this is less common on mobile).