Disco Light Configuration does not work properly

Hi all,

my disco light automation doesnt work as I expected. I am using rgb zigbee spots and a conbee2 as zigbee gateway.
What I expected:
The colors and brightness of the spots are changing randomly every two seconds.
What I get:
If I activate the party automation, the spots are changing colors very quickly and after ~5sec they changing the color randomly every 5 or 3 or 6 seconds. Not every two seconds…

Automation:

alias: Party on Script - Terrasse
description: ''
trigger:
  - platform: state
    entity_id:
      - input_boolean.partymode_terrasse
    to: 'on'
condition: []
action:
  - service: scene.create
    data:
      scene_id: pre_party_terrasse
      snapshot_entities:
        - light.terrasse_deckenlampe1
        - light.terrasse_deckenlampe2
        - light.terrasse_deckenlampe3
        - light.terrasse_deckenlampe4
        - light.terrasse_deckenlampe5
    enabled: true
  - repeat:
      while:
        - condition: state
          entity_id: input_boolean.partymode_terrasse
          state: 'on'
      sequence:
        - service: script.turn_on
          data: {}
          target:
            entity_id: script.party_on_terrasse
        - delay:
            hours: 0
            minutes: 0
            seconds: 2
            milliseconds: 0
mode: single

Script:

alias: Party on - Terrasse
sequence:
  - service: light.turn_on
    target:
      entity_id: light.terrasse_deckenlampe1
    data:
      rgb_color:
        - '{{ (range(0, 255)|random) }}'
        - '{{ (range(0, 255)|random) }}'
        - '{{ (range(0, 255)|random) }}'
      brightness: '{{ (range(50, 250)|random) }}'
      transition: 0.1
  - service: light.turn_on
    target:
      entity_id: light.terrasse_deckenlampe2
    data:
      rgb_color:
        - '{{ (range(0, 255)|random) }}'
        - '{{ (range(0, 255)|random) }}'
        - '{{ (range(0, 255)|random) }}'
      brightness: '{{ (range(50, 250)|random) }}'
      transition: 0.1
  - service: light.turn_on
    target:
      entity_id: light.terrasse_deckenlampe3
    data:
      rgb_color:
        - '{{ (range(0, 255)|random) }}'
        - '{{ (range(0, 255)|random) }}'
        - '{{ (range(0, 255)|random) }}'
      brightness: '{{ (range(50, 250)|random) }}'
      transition: 0.1
  - service: light.turn_on
    target:
      entity_id: light.terrasse_deckenlampe4
    data:
      rgb_color:
        - '{{ (range(0, 255)|random) }}'
        - '{{ (range(0, 255)|random) }}'
        - '{{ (range(0, 255)|random) }}'
      brightness: '{{ (range(50, 250)|random) }}'
      transition: 0.1
  - service: light.turn_on
    target:
      entity_id: light.terrasse_deckenlampe5
    data:
      rgb_color:
        - '{{ (range(0, 255)|random) }}'
        - '{{ (range(0, 255)|random) }}'
        - '{{ (range(0, 255)|random) }}'
      brightness: '{{ (range(50, 250)|random) }}'
      transition: 0.1
mode: single