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
A minority of clients having incorrect operating system information which was overriding correct data in the database.
Release : 14.3 RU4
This issue will be fixed in 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, please open a support ticket and reference this document.