After upgrading Symantec Endpoint Protection Manager (SEPM) to 14.3 RU4, the "operating system" variable is blank when viewing the report. In addition, it is also missing in the export of the "computer status" log.
Symantec Endpoint Protection 14.3 RU4
A minority of clients having incorrect operating system information which was overriding correct data in the database.
This issue is fixed in Symantec Endpoint Protection 14.3 RU5. Please upgrade to this version to take advantage of the fix.
If you are unable to upgrade, there is a workaround available for version 14.3 RU4; please open a support ticket and reference this document.