You may need to reset a Genius Smart Plug if you are swapping which Genius Hub the Smart Plug is included onto.
To factory reset a Genius Smart Plug:
When you unplug the Genius Smart Plug and plug it back in again, then the front button will slowly flash showing that it is not connected to any network.
The Genius Smart Plug is now in a factory reset to default state, to add it back onto the system again go to the 'Doctor' on the app which is under the 'Main Menu'.
For more information see this article.