IFTTT won't switch on scenes

Configuration
1

The example webhook works fine:
{ “action”: “call_service”, “service”: “light.turn_on”, “entity_id”: “light.living_room” }
But this doesn’t work:
{ “action”: “call_service”, “service”: “switch.turn_on”, “entity_id”: “switch.all_lights” }
Where “switch.all_lights” is an ISY scene. In developer mode, this works perfectly, but when IFTTT sends the webhook it’s ignored?
Here is the automations code:

- id: '11110000'
  alias: IFTTT lights on
  trigger:
  - platform: event
    event_type: ifttt_webhook_received
    event_data:
      action: call_service
  condition: []
  action:
  - service: '{{ trigger.event.data.service }}'
    target:
      entity_id: '{{ trigger.event.data.entity_id }}'