You may have a test and production environments configured to share the same GPOADmin server and Version Control.
Upon creating a GPO in the test environment, with a WMI Filter enabled, then exporting it to the production environment, the WMI Filter disappears but a it will still come up listed under the GPO’s history.
WMI Filters are unique to each environment, meaning they hold a specific GUID. By importing a GPO (with the filter enabled) to another environment, the specific filter is removed.
The history though is carried over to the new environment and will show a WMI filter applied, as the last historical backup would show the WMI filter.
This could lead to the appearance of an inconsistency between the settings and the history, however this is considered normal product behavior as product will not go back and remove the previous WMI filter settings from the old history when it is stripped during the import.
WORKAROUND
Manually re-add the desired WMI Filter to the imported GPO.
