Batch Update non working

Hi everybody,

I'm trying to do a batch update in a sharepoint solution on sharepoint 2013.

This is not working properly so I'm now testing basics things.

What I'm testing is trying to change the title of an item via batch update via powershell.

Here is my update

<?xml version="1.0" encoding="UTF-8"?><ows:Batch OnError="Return"><Method ID="A1"><SetList>e30befd2-9a06-4d0e-80ec-85ec63486d8b</SetList><SetVar Name="ID">3</SetVar><SetVar Name="Cmd">Save</SetVar><SetVar Name="urn:schemas-microsoft-com:office:office#Title">New Manager</SetVar></Method></ows:Batch>

Here is my powerhsell script to do so

$batch = get-content .\batch.txt
$web.AllowUnsafeUpdates =$true
$web.ProcessBatchData($batch)
$web.AllowUnsafeUpdates =$false

here is the return I get

<Results><Result ID="A1" Code="0"></Result></Results>

but the title is not updated. The list is a simple custom list with only the standard fields. The guid is correct (got it via powershell) and the item id is correct too (same thing).

I also tested under sharepoint 2010 having the same issue. So I think I might be doing something wrong at some point but I don't know what.

Thank you for your help.

Cya