Widget won't update status

[wertzui]

I have a toggle switch triple horizontal at position 7 as a group by sending the following to /nspanel/cmd/nspsend:

{
  "HMI_resources": [
    {
      "index": 7,
      "ctype": "group",
      "id": "7",
      "uiid": 3
    }
  ]
}

I've also set all the other widgets in the correct order from 1 to 8 (so the message for 7 was the 2nd to last message).

It correctly shows up on the NSPanel and when I touch "OUTLET 3", it turns on and the following message is received on /nspanel/RESULT:

{
  "NSPanel": {
    "ctype": "group",
    "id": "7",
    "params": {
      "switches": [
        {
          "switch": "off",
          "outlet": 0
        },
        {
          "switch": "on",
          "outlet": 1
        },
        {
          "switch": "off",
          "outlet": 2
        }
      ]
    }
  }
}

After a couple of seconds, the "OUTLET 3" is turned off on the screen.

I now want to manipulate the status of "OUTLET 3" through an MQTT message.
I'm sending the following to /nspanel/cmd/nspsend:

{
  "relation": {
    "ctype": "group",
    "id": "7",
    "params": {
      "switches": [
        {
          "switch": "off",
          "outlet": 0
        },
        {
          "switch": "off",
          "outlet": 1
        },
        {
          "switch": "on",
          "outlet": 2
        }
      ]
    }
  }
}

I get the following back on /nspanel/RESULT:

{
  "NSPSend":"Done"
}

However the status of "OUTLET 3" on the screen is still "off".
What do I need to change here to get it working?