If an end user adds a firewall rule to a Symantec Endpoint Protection (SEP) 14.2 client, which is in Mixed Control Mode, the rule works as expected until the device is restarted. Restarting the SMC service will also cause the rule to stop being processed. If the rule is modified in any way, then saved, it will begin working again until the device is restarted or SMC restarts.
This issue is fixed in Symantec Endpoint Protection 14.2 RU1. For information on how to obtain the latest build of Symantec Endpoint Protection, see Download the latest version of Symantec Endpoint Protection.
Modifying the affected rule in anyway, then saving the rule will resolve the issue until the device is restarted again.