OK, that explains the lack of the lock status indicator.
I wonder if there is another property that comes later in the list that overrides the class.
Could you go through the add device procedure, up as far as seeing a list of devices (ne need to actually add a device). This will log the data returned by the devices.
To view the log go to More > Apps > SmartThings Hub > Configure App and then select the Detected tab. Copy the contents and send them to me via a PM.
Edit: you can also view the app configuration at Homey Developer Tools
