Office 365 - Remove Mobile Devices older than 180 days

Running the following script

$oldDevices = Get-MobileDevice -resultsize unlimited |
    Get-MobileDeviceStatistics |
    where {$_.LastSuccessSync -le (Get-Date).AddDays("-180")}

$OldDevices | foreach-object {
    if ($Warn)
        $null = $Warn.Message -match "Actual delayed:\s(?'Delay'[0-9]+)\s"
        Start-Sleep -Milliseconds $Matches.Delay
        $Warn = $null
    Remove-MobileDevice ([string]$_.Guid) -confirm:$false -WarningVariable Warn

I don’t know What I am missing but I am getting the following result:

The operation couldn't be performed because 'USER\ExchangeActiveSyncDevices\REST§Outlook§7b723c9dbd7efbc1c4ded78588a7f9c6' matches multiple entries.
    + CategoryInfo          : NotSpecified: (:) [Get-MobileDeviceStatistics], ManagementObjectAmbiguousException
    + FullyQualifiedErrorId : [Server=DM5PR1001MB2105,RequestId=58acfc5a-068a-489a-a2d5-3d559eae8295,TimeStamp=1/3/202
   0 9:46:01 PM] [FailureCategory=Cmdlet-ManagementObjectAmbiguousException] 5B1053DA,Microsoft.Exchange.Management.T
    + PSComputerName        :

You can also reference $_.Guid.Guid to get to the right level of the object.

Is your warning variable capturing the throttling message? I swear I tried that long ago and it didn’t work.