You installed Symantec Endpoint Protection (SEP) 14.0.x Dark network client on Windows machine.
But Install type of this SEP client is displayed as "Standard" client on SEPM console - Client tab - <Group Name> - [Clients] tab in right pane - change View as "Protection Technology" then open client property.
If you choose other view than "Protection Technology", the same client is displayed as "Dark network" client correctly.
Symantec Endpoint Protection Manager 14.0
This issue is fixed in Symantec Endpoint Protection 14.2. For information on how to obtain the latest build of Symantec Endpoint Protection, see Download the latest version of Symantec Endpoint Protection.