Scene names with space not activated from automation

Configuration
1

I want to set a scene dependent from a dropdown.
When the list value is only one word Aus or Fernsehen it activates the scene Aus bzw. Fernsehen.
But, when there is a space Licht Aus or underscore Licht_Maximal. I do not get it to work.
How the {{trigger.to_state.state}} must be formatted?

Automation

  trigger:
  - platform: state
    entity_id:
    - input_select.scenes_bedroom
  condition: []
  action:
  - service: scene.turn_on
    data_template:
      entity_id: scene.{{trigger.to_state.state}}
  mode: single

Dropdown:

input_select:
  scenes_bedroom:
    name: Bedroom Lights
    options:
      - Aus
      - Nachtlicht
      - Fernsehen
      - Maximal
    initial: Aus

Scenes:

- id: '1637152617811'
  name: Aus
  entities:
 ...

Thank you
Christian