After installing SEP for Mac as a managed client, you see that the computer is successfully communicating but that the machine name that displays in the SEPM (Symantec Endpoint Protection Manager) is incorrect.
There may be a variety of names that identify a macOS system. The SEPM will list Mac clients by their LocalHostName as retrieved from macOS settings.
Running the following Terminal commands on a Mac will demonstrate the different names that are set for that system. Normally the names match, but not necessarily:
scutil --get ComputerName
# The user-friendly name for the system. This is normally what is displayed in macOS Preferences -> Sharing, "Computer Name".
scutil --get LocalHostName
# The local (Bonjour) host name; This what is displayed in the SEPM. This is used in the form of LocalHostName.local to access the Macintosh via Apple's Bonjour networking. This name will be displayed below the Computer Name in macOS Preferences -> Sharing.
scutil --get HostName
# The name associated with hostname and gethostname commands. This is the name normally displayed as a prefix to command lines in the macOS Terminal. HostName is also normally the name that is registered to DNS servers and AD/LDAP directories, but those directories may use even other aliases to refer to this computer.
To change any of the above names, use the following command, e.g.:
sudo scutil --set LocalHostName NewName
NetBIOS/WINS is yet another name that may identify a Macintosh system. This is displayed and set in macOS Preferences -> Network, Advanced, WINS, NetBIOS Name.
All of these names may be completely different. Best practices would encourage using matching names, but naming conventions may require otherwises. The only name that the SEPM uses to list a Macintosh in its client list is the LocalHostName set in the Macintosh's local system preferences. The HostName, ComputerName, NetBIOS, or DNS/AD/LDAP names to not matter to the SEPM.
Using the instructions above, set the Macintosh LocalHostName in the macOS settings to match the name that you wish to appear in the SEPM client list. At next SEP heartbeat, the SEPM client list should change to match. Optionally change other names to match the LocalHostName to avoid confusion.