Brightness change for OSRAM LED brightness_decrease not working

Configuration
,
1

Hi all,
I am trying since several days to get a brightness decrease working on an OSRAM LED via automation.

The LED brightness can be changed via the FrontEnd/Light card without any problem via slider.

But all my appoaches fail to use the ‘brightness_decrease’ action in the automation configurator.

My 1st approach - and the auto-created YAML without changes:

alias: automation003
description: ""
trigger:
  - device_id: a8fdd70122f82e513643f74388794a82
    domain: deconz
    platform: device
    type: remote_button_long_press
    subtype: turn_on
condition: []
action:
  - device_id: 544f64f528d4423f83f03b283f80ca38
    domain: light
    entity_id: light.licht_01
    type: brightness_decrease
mode: single

I tried additionally in my 1st customized (failed) approach

alias: automation003
description: ""
trigger:
  - device_id: a8fdd70122f82e513643f74388794a82
    domain: deconz
    platform: device
    type: remote_button_long_press
    subtype: turn_on
condition: []
action:
  - device_id: 544f64f528d4423f83f03b283f80ca38
    domain: light
    entity_id: light.licht_01
    brightness: 50     // or '50'
mode: single

But all these approaches give an error message like

Message malformed: extra keys not allowed @ data[‘brightness’]

or with

action:
  - device_id: 544f64f528d4423f83f03b283f80ca38
    domain: light
    entity_id: light.licht_01
    data:
      brightness: 50
mode: single

Message malformed: extra keys not allowed @ data[‘data’]

Any ideas, how to get the LED brightness changed ?? :slight_smile:
btw the automation setup to sitch the light off/on/toggle the state works perfect, without any modification required.

Greets
Joerg