Bitlocker recovery information retrievement

Hello,
we are using a vbs script (downloaded from Microsoft) to retrieve Recovery information stored in AD.
The script is working well under admin account but not under SYSTEM account.

All rights delegation for Bitlocker are done (AD group where the working admin account is present we put also the computer account/s)

Script:
Set objDSO = GetObject("LDAP:")
strPathToComputer = GetStrPathToComputer (strComputerName)
 
 WScript.echo
 WScript.Echo "Accessing object: "  + strPathToComputer  & " to compare found ID and PWD with Active Directory"
 
Const ADS_SECURE_AUTHENTICATION = 1
Const ADS_USE_SEALING = 64 '0x40
Const ADS_USE_SIGNING = 128 '0x80
 
 
' --------------------------------------------------------------------------------
' Get all BitLocker recovery information from the Active Directory computer object
' -------------------------------------------------------------------------------
 
' Get all the recovery information child objects of the computer object
 
Set objFveInfos = objDSO.OpenDSObject (strPathToComputer, vbNullString, vbNullString, ADS_SECURE_AUTHENTICATION + ADS_USE_SEALING +  ADS_USE_SIGNING)

wscript.echo err
 
objFveInfos.Filter = Array("msFVE-RecoveryInformation")
 
' Iterate through each recovery information object  

      
For Each objFveInfo in objFveInfos
 
      strName = objFveInfo.Get("name")
 
      strRecoveryGuidOctet = objFveInfo.Get("msFVE-RecoveryGuid")
      strRecoveryGuid = ConvertOctetGuidToHexString (strRecoveryGuidOctet)
 
      strRecoveryPassword = objFveInfo.Get("msFVE-RecoveryPassword")
 
      WScript.echo  
      WScript.echo "name: " + strName  
      WScript.echo "msFVE-RecoveryGuid: " + strRecoveryGuid
      WScript.echo "msFVE-RecoveryPassword: " +  strRecoveryPassword
   
 
      If len(strRecoveryGuid) <> 38 Then
      WScript.echo "WARNING: '" &  strRecoveryGuid & "' does not appear to be a  valid GUID."
                    End If

      If strRecoveryGuid = vKeyProtectorID Then
            If strRecoveryPassword = numPWD Then
                  wscript.echo "Correct ID And PWD found"
                  Wscript.Quit 0
            End If
      End If
Next

Seems that objFveInfos  is empty when script is started under SYSTEM account.
Do you have any idea?
Thanks