@Alwin This is the default behavior of the Extension. During extension initiation it fires off the Notification Con Job. Disabling the Automatic Audit doesn’t control Notifications you are simply telling the extension to not audit your sites.
Instead, you will want to navigate to MainWP > Settings > Email Notifications > LightHouse Notification Email > Manage > Disable the email notifications.
Are you sure this is default behavior of the Extension. Yesterday I mobed my MainWP dashboard from local host to Cloudways hosting, and the problem is solved, without editing the Email setting (wich are enabled for the extension).