Vontu Enforce services will not start automatically after the server reboot even if the services are set to Automatic within Windows services.
The protect user is not assigned to "Log on as a service" inside the local security policy and/or group policy on the Enforce server.
To resolve the issue assign the protect user to "Log on as a service" policy inside the local security policy.
Note : If the server is in workgroup and you remove the protect user from local security policy mmc, then it will also be removed local group policy however if it is there in the domain then group policy will take the precedence over local security policy. You might see the protect and protect_update in local security policy but you will not see in the gpedit.msc. This issue appears where hardening of the server is performed using GPO.
Symantec Data Loss Prevention Enforce