That looks like it might be a problem with WMI, not PowerShell. Have you tried using Invoke-CIMMethod (using the same class name)? It may not make any difference, but it's easy enough to try. The WMI and CIM may use different MOF files to acquire the and process the information.
Or it may be a problem with the installed languages on the RDS server (where the report is created). But that's a Windows configuration issue, not a PowerShell problem.