I tested something just now. I turned the switch on manually and it didn’t show the change in smartthings as you said. I then created a CoRE piston that refreshes the state of the smart plug every minute and allowed it to run and sure enough being allowed to run it then showed the state change in smartthings. Again the communication seems to have to be triggered from within smartthings but it’s not detrimental to the device’s function but it would be good if it would update its state on its own without prompting.