Kerio Control 9.4.2 -

: Some users report significant speed drops (e.g., from 200 Mbps down to 100 Mbps) behind the firewall, even when QoS limits are disabled.

If you are still running 9.4.0 or 9.4.1, upgrading to 9.4.2 is (if not mandatory) to avoid these operational headaches. kerio control 9.4.2