Tellstick Duo not working with Ikea Koppla

Installation Home Assistant OS
1

Trying to use my old Ikea Koppla switches with Tellstick Duo in hassio. In the add-on config I have:

    {
      "id": 37,
      "name": "Cinema",
      "protocol": "ikea",
      "fade": "true",
      "system": "1",
      "units": "1"
    }

but after save and restart, the system and units get lost:

    {
      "id": 37,
      "name": "Cinema",
      "protocol": "ikea",
      "fade": "true"
    }

The switch does not load. No errors in the log.

I realise this is old hardware, but the docs suggest it is supported.

2

Sorted it! Had forgotten to add the light domain to config.yaml.