I can’t control the switch from Config, Developer Tools, States, Set State.
I can see the state changing when pressing the button on the switch or publishing an MQTT message.
It’s not a problem. Since I can control the entity from a card in Lovelace, it is more of a curiosity.
The problem, it turns out, was that the Kuled switch was not connecting to my WiFi network.
I described the solution process here on the OpenBeken website.