You need to remove the X-Bluecoat-Via header from a specific location in Web Security Services (WSS) so that this information is not transferred by the proxy. This article describes how to do this for Universal Policy Enforcement (UPE) configuration. If this needs to be done only for WSS, the configuration change needs to be carried out by Symantec Technical Support.
Symantec Universal Policy Enforcement (UPE) - Management Center + WSS
define condition BC_ocs_fix_broken_by_via_header