On the Symantec Endpoint Detection and Response (EDR) appliance you are unable to select a SEPM group for a Recorder Group Exception or an Endpoint Search. The issue occurs if the SEPM group has one or more child groups, regardless if the child group(s) inherit from the parent group.
SEPM: 14.3 RU3 build 5427 - 14.3 RU4
The SEPM API returns an unexpected error when querying for the list of SEPM groups.
Issue fixed in 14.3 RU5 version.