Using Windows Server 2012 per-User RDS CAL on Server 2008 R2 Session Host

I have a Remote Desktop Licensing Server setup on my domain controller running Windows Server 2012 R2. I have installed a’Windows Server 2012 Remote Desktop Services per-User CAL’ there and activated the licensing server already.

Currently I use ONLY Windows Server 2008 R2 machines as RDS Session Hosts (in the future I plan to transition them to 2012 R2, hence the CAL I bought is already in the newest version).

I have already configured my WS 2008 RDS Session Hosts: setPer-User licensing mode and specified license server address. The connectivity between my Session Host(s) and my License Server seems to be ok as theRemote Desktop Session Host Configuration window on the Session Host correctly lists the 2012 per-userlicense (CAL installed on server) from the license server.

On the License Server I can also see event logs entries (inMicrosoft-Windows-TerminalServices-Licensing/Admin), indicating that the user has been issued a license.

The issue I am having is that the license being issued is2008 Per User CAL license (Build-in OverUsed - temporary) and not the 2012 Per User CAL license which is the only license installed on the server. According to the RDS CAL interoperability matrix atsocial.technet.microsoft.com/wiki/contents/articles/14988.rds-and-ts-cal-interoperability-matrix.aspx, I was expecting the 2012 license to be backward-compatible with 2008 client (and that in the absence of legacy licenses, the (only) 2012 license would be used for all clients connecting to the licensing server)

Before I bought my license, I found this document: 

download.microsoft.com/download/3/D/4/3D42BDC2-6725-4B29-B75A-A5B04179958B/WindowsServerRDS_VLBrief.pdf 

which says that - "newer version RDS CALs can be used with an older version of the server software" (In section FAQ, Q4), which means to me that the 2012 license would work as-is for the 2008 Server and gives me flexibility when upgrading to the new server version.

How can I make this CAL work in my environment? 

Note:

I have already explicitly disabledPrevent license upgrade Group Policy setting which I assumed would fix the issue but nothing has changed.
Then I have enabled License server security group Group Polity setting and added computers from my domain to RDS Endpoint Servers AD group. I have also created new AD group calledTerminal Server Computers and added the computer accounts there, but it changes nothing. Reference - technet.microsoft.com/en-us/library/ee791761.aspx , technet.microsoft.com/en-us/library/cc725704.aspx and blogs.msdn.com/b/rds/archive/2009/09/17/control-the-issuance-of-rds-cals.aspx.

I found one potential ‘workaround’ which involved manually downgrading my CAL license by calling Microsoft Clearinghouse. I am very reluctant do to so because, as I upgrade parts of my infrastructure to Server 2012, I’d need to then ask Microsoft to manually upgrade a part of my license back as well.