I wasn't enabling the Oculus Online Subsystem 😓 .. that took way longer than it should have to fix
Previously, I would use the 'Oculus VR' plugin Verify Entitlement node.
In 4.27, we now have the 'Oculus OpenXR' plugin, and this node is no longer available (?) We are told explicitly to "Disable the Oculus VR plugin when enabling" the 'Oculus OpenXR' plugin.. sooo.... how am I to do the required entitlement check??