Remote Desktop Services: Session Time limits not working

Hi All,
I'm facing an issue with the "Set time limit for disconnected sessions" under "Configuration, Admin Templates, Windows Components, Remote Desktop Services, Remote Desktop Session Host, Session Time Limits".
The policy is correctly applied on all servers via GPO (and I can see the correct value in the registry key), but seems like some servers doesn't respect the disconnection timeout.

The servers where the policy seems to work are those running the "Remote Desktop Services" server role.
Server without that server Role that only have the built-in RDP admin feature enable (2 free connection) seems to skip the session timeout limits.

Is this correct?
Are those policies only for servers with the full "Remote Desktop Services" server role.

Thanks