Hello WPMU Support!
The Defender Pro is setting a site transient valid for one hour, in wp-defender/app/behavior/utils.php:703
This is running into in endless loop in our environment, as every request seems to start a new Request with again new detection of the Apache version. So our sites were down every 3600 seconds until the monitoring restarts the servers. So please check if this endless loop can be avoided, or just set the expiration to 0. There is no need to determine the Apache version hourly probably.
Kind Regards
David Stiller
