Your Railway-provided domains are resolving correctly from the public internet, and your deployments show as running successfully. The "server IP address could not be found" error is a local DNS resolution failure on your device or network. Try flushing your local DNS cache (ipconfig /flushdns on Windows or sudo dscacheutil -flushcache on macOS), testing in an incognito window, or trying a different network or DNS resolver (e.g., 1.1.1.1 or 8.8.8.8).