On computers that tunnel DNS requests through Cisco Umbrella DNS service, Web browsing is slow when connecting to Symantec Web Security Services (WSS) through the Symantec Endpoint Protection (SEP) client's Web Traffic Redirection (WTR). Loading several web sites at once may take up to a minute or longer.
Some Web browsers, such as Google Chrome, may show status messages saying "Waiting for proxy server". Explicit proxy connections to WSS do not show the same delays.
Use the LPSFlags.exe tool to reconfigure the SEP client's proxy.pac file to bypass the Umbrella DNS servers. For more information on the LPSFlags.exe tool see Bypass Endpoint Protection Web Traffic Redirection using LPSFlags.exe.
For more information about Cisco's Umbrella DNS and HTTP proxies, refer to the following documentation: https://support.umbrella.com/hc/en-us/articles/230563527-Using-Umbrella-with-an-HTTP-proxy