Fail to get the script result

I would suggest going thru LM's WMI troubleshooting guide at https://www.logicmonitor.com/support/monitoring/os-virtualization/troubleshooting-wmi, especially the WBEMTEST testing step and check that you can get any results from Win32_PerfRawData_PerfOS_System directly. If I was going to take a blind guess, you may need a WMI Counter Repair since other checks work.