The fact that your HC2 controller is auto adding it, could be what is stopping it from being added to Homey (as its already in a controller).
They do not make Everspring AD142-3 for my country, try toggling the plug on/off 5-10 times in a row. Or Holding down the button, or toggling the button 5-10 times. There will be a way to reset its connection.
Last I can suggest you check out the other threads : https://community.homey.app/search?q=Everspring
