Some Mac clients do not appear from the Clients view of Symantec Endpoint Protection Manager (SEPM) console, but you can find them with via search or by in reports or logs.
If you are filtering the SEPM Clients view by operating system type—even if you have included "Show Mac"—macOS 11 "Big Sur" clients will be hidden.
Release : 14.3 RU1
Symantec is aware of this issue and will update this document as new information becomes available.
You can work around the issue by viewing the SEPM Client list unfiltered.