A firewall can block the scanner so it can’t start scanning. Sometimes, the scanner may send many requests and a firewall could see this as a DDoS attack.

A distributed denial-of-service (DDoS) attack is a malicious attempt to shut down a server, service, or network by overloading it with too much internet traffic, making it hard for normal users to access.

Make sure your site's firewall isn’t blocking our scanners' IP address so it can scan your domain correctly. This IP address is 20.224.113.102.

You can avoid this issue by whitelisting our scanner in your firewall.