Unexpected error in automation: [round_digits] is an invalid option for [automation]

using this:

automation:
  - alias: Ventileren
    id: 'Ventileren'
    trigger:
      platform: numeric_state
      entity_id: sensor.luchtvochtigheid_living
      above: 55
      for:
        minutes: 30
    condition:
      - condition: template
        value_template: >
          {{ states('sensor.schimmel_sensor')|float > 50 }}
      - condition: template
        value_template: >
          {{ is_state('input_boolean.notify_utility', 'on')}}
    action:
      service: notify.notify
      data_template:
        title: Ventileren
        message: >
          Ventileren! {{states('sensor.schimmel_sensor')}} % kans op schimmel en {{states('sensor.luchtvochtigheid_living')}} % rel. vocht.

which I believe complies 100% with https://www.home-assistant.io/docs/automation/trigger/#numeric-state-trigger

results in this error is in the logs:

Invalid config for [automation]: [round_digits] is an invalid option for [automation]. Check: automation->round_digits. (See /config/configuration.yaml, line 47). Please check the docs at https://home-assistant.io/components/automation/

never seen this before, and this is almost an exact copy of another automation which doesn’t complain… have already tested each individual part of the automation, but it keeps failing, while showing the desired outcome in the dev-template…

what’s wrong here, and why does it state the automation uses [round_digits] ?
is it the schimmel sensor itself maybe:

  - platform: mold_indicator
    name: Schimmel sensor
    indoor_temp_sensor: sensor.temperatuur_living
    indoor_humidity_sensor: sensor.luchtvochtigheid_living
    outdoor_temp_sensor: sensor.br_temperature
    calibration_factor: 1.16

_UPDATE

nevermind… a line hidden below the window of the text editor revealed the round_digits. Cant delete this post, so explained why I was being silly. Beg your pardon…