On the Windows target, verify that the OMI service is running and the WMI bridge is enabled:

omi new root/cimv2 Win32_OperatingSystem

omi query "SELECT * FROM Win32OperatingSystem" -n root/cimv2

Does OMI restrict access to certain system classes, or is there a namespace difference between OMI and WMI? Any guidance on getting this working would be appreciated.

Any management tool that fails to retrieve this class loses a critical baseline of system information.