Beginning with the Unified Agent version 4.4, Blue Coat introduced a new feature that allows the Unified Agent to take advantage of the Domain Bypass list in the portal. Before version 4.4, the only bypass option available was to bypass by IP address.
This new feature requires the Unified Agent to listen for all DNS requests that are made by the workstation.
The following symptoms might occur:
A new version (4.9.4) of Unified Agent which was released on Feb 2 2018 will resolve this issue.