Creating ADMX backed Configuration policies

I am trying to figure out how to create an ADMX backed Config Profile in Intune to disable the weather and stock information that is now sent to the Windows 11 lock screen but I cannot get it to work.  According to this post, I should use the WindowsLogon/DisableLockScreenAppNotifications CSP.  This article describes the CSP configuration and as it is an ADMX backed policy, it requires SyncML format to configure.  Between this article and this article, I created a custom Config Profile like below,

Name: Disable App Notifications

Description: Blank

OMA-URI: ./Device/Vendor/MSFT/Policy/Config/WindowsLogon/DisableLockScreenAppNotifications

Data Type: String

Value: 

<SyncML xmlns="SYNCML:SYNCML1.2">
<SyncBody>
<Replace>
<CmdID>2</CmdID>
<Item>
<Meta>
<Format>chr</Format>
<Type>text/plain</Type>
</Meta>
<Target>
<LocURI>./Device/Vendor/MSFT/Policy/Config/WindowsLogon/DisableLockScreenAppNotifications</LocURI>
</Target>
<Data><Enabled/></Data>
</Item>
</Replace>
<Final/>
</SyncBody>
</SyncML>

I've deployed it to my user account first and after it failed, I deployed it to my device where it also failed.  The event log shows this error in both cases

Can anyone please help tell me where I am going wrong?  

Thanks in advance