WMI Works From PowerShell But PRTG Interface Shows Error

I'm having this problem with a number -- although not all -- of Windows 2012 R2 servers. For the WMI sensors for CPU Load and Pagefile Usage I'm getting this through the PRTG interface:

The WMI query does not return any results. The reason might be an issue with the host's WMI system. For more information, see https://kb.paessler.com/en/topic/1093. (code: PE016)

I've been through that and done many of the (less drastic) things suggested there. None of them have helped. The really confusing thing, though, is using PowerShell from the PRTG server returns values!

PS C:\Windows\system32> $adminaccount = "[hostname]\monitor"
PS C:\Windows\system32> $PASSWORD = ConvertTo-SecureString [password] -AsPlainText -Force
PS C:\Windows\system32> $UNPASSWORD = New-Object System.Management.Automation.PsCredential $adminaccount, $PASSWORD
PS C:\Windows\system32> Get-WmiObject -query "SELECT * FROM Win32_PageFileUsage" -ComputerName "[IP address]" -Credential $UNPASSWORD

Caption                                 Name                                                                  PeakUsage
-------                                 ----                                                                  ---------
C:\pagefile.sys                         C:\pagefile.sys                                                            1642

I'm mystified as to why this would work perfectly, just not through PRTG. Any ideas?

pe016 prtg wmi