wordfenceプラグインでスキャンできない

下記メッセージが出て、スキャンができません。
原因は何でしょうか？
WordPressバージョン：6.1
PHPバージョン：7.4.28
プラグインバージョン：7.7.1

「Scan Stage Failed
A scan stage has failed to start. This is often because the site either cannot make outbound requests or is blocked from connecting to itself. Wordfence will make up to 2 attempts to resume each failed scan stage. This scan may recover if one of these attempts is successful.」