WMI queries random access denied - powershell

Question

Why does the Win32_Service WMI query randomly fail with deny access to my WMI Queries.
I'm running a Win32_Service WMI query daily against several different domains. Today I've noticed that the query failed in one DOMAIN because it was denied access. When I run the queries in a loop they fail at times that seem random to me. It will run successfully, fail once or twice and then run successfully again. So far I have only seen this occur in one of the domains I am checking.
This is the error message
Friday, December 09, 2016 2:33:26 PM
Get-WmiObject : Access is denied.
(Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))
At C:\junk\Untitled2.ps1:23 char:22
+ $Service_Data = Get-WmiObject `
+ ~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Get-WmiObject], UnauthorizedAccessException
+ FullyQualifiedErrorId : System.UnauthorizedAccessException,Microsoft.PowerShell.Commands.GetWmiObjectCommand
This is the template for what I'm running
$loopDelay = 60
$userName = 'Domain1\LocalAdmin'
$pwd = 'Password'
$Sec_Pwd = $pwd | ConvertTo-SecureString -AsPlainText -Force
$Creds = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList $UserName, $Sec_Pwd
$Servers = #()
$Servers += "Server1.Domain1.org"
$Servers += "Server2.Domain1.org"
$Servers += "Server3.Domain1.org"
$Servers += "Server4.Domain1.org"
while (1 -eq 1)
{
Get-Date
$Service_Data = Get-WmiObject -Credential $creds -ComputerName $Servers Win32_Service |
where {$_.Name -eq "JunkTest"} |
select SystemName, State, Status
$Service_Data | Format-Table
"<Ctrl><C> to quit"
sleep 60
}