Media_player volume_set loop stuck at specific value

Configuration
1

Hey I am trying to make a loop to make my spotify media player louder over time but somehow it gets stuck at 0.57. I have no clue why. Does anyone have an idea?

repeat:
  count: '30'
  sequence:
    - service: media_player.volume_set
      entity_id: media_player.spotify
      data_template:
        volume_level: >-
          {{ (states.media_player.spotify.attributes.volume_level  + 0.01)
          | round(2) }}
    - delay:
        hours: 0
        minutes: 0
        seconds: 3
        milliseconds: 0
    - service: light.turn_on
      target:
        entity_id: light.bed
      data:
        brightness_step_pct: 2
        color_temp: '{{ states.light.bed.attributes.color_temp - 6 }}'

The trace looks like this:

Iteration 10
Executed: December 22, 2021, 14:04:59
Result:

params:
  domain: media_player
  service: volume_set
  service_data:
    volume_level: 0.55
    entity_id:
      - media_player.spotify_lukas
  target:
    entity_id:
      - media_player.spotify_lukas
running_script: false
limit: 10

Iteration 11
Executed: December 22, 2021, 14:05:02
Result:

params:
  domain: media_player
  service: volume_set
  service_data:
    volume_level: 0.56
    entity_id:
      - media_player.spotify_lukas
  target:
    entity_id:
      - media_player.spotify_lukas
running_script: false
limit: 10

Iteration 12
Executed: December 22, 2021, 14:05:06
Result:

params:
  domain: media_player
  service: volume_set
  service_data:
    volume_level: 0.57
    entity_id:
      - media_player.spotify_lukas
  target:
    entity_id:
      - media_player.spotify_lukas
running_script: false
limit: 10

Iteration 13
Executed: December 22, 2021, 14:05:09
Result:

params:
  domain: media_player
  service: volume_set
  service_data:
    volume_level: 0.57
    entity_id:
      - media_player.spotify_lukas
  target:
    entity_id:
      - media_player.spotify_lukas
running_script: false
limit: 10

After this there are only 0.57 following.