Even when dig shows correct records, verification can still fail due to CAA records blocking Let's Encrypt or DNSSEC misconfigurations. Check for CAA records with dig CAA yourdomain.com and if any exist, ensure one includes letsencrypt.org as the issuer. Also run your domain through dnsviz.net to check for DNSSEC chain errors. If you're using Cloudflare, try temporarily disabling the proxy (grey cloud) on your domain's DNS record, wait for the green checkmark to appear in Railway, then re-enable the proxy. Avoid deleting and re-adding the domain repeatedly as Let's Encrypt enforces strict rate limits that could block certificate issuance for 7 days.