Using Symantec Endpoint Protection (SEP) 14 RU1 MP1 or higher, you find that its Web Security Services (WSS) Traffic Redirection (WTR) feature is not enabled for more than 10 minutes following a location switch that results in a WTR transition attempt from a disabled to an enabled stated. You find that this happens for both Internet Explorer and Chrome. All the while, the browsers are unable to use the proxy.
This issue was resolved in WTR engine 1.1.0.187.