"Request failed with status code 400"

[djpole]

I have various Shelly Plug Plus S (model with power meter). I use Node-Red, and I control the relay state with a function with the next code:

msg.payload = {
method: "Switch.Set",
parameters: {
id: 0,
on: true
}
}
return msg;

This always worked perfect, but some weeks ago it fails: the switch doesn´t change the status and I get the response "Request failed with status code 400" in the console. I have made no change in my flows, so I don´t know why it fails.

I don´t know what to do. Please help.