Alexa volume not adjusting?

Configuration
1

I have this automation, but it doesn’t seem to set volume to 0. Anyone got this to work ?

id: '1643641012752'
alias: Set day volume of speakers when working in office
description: >-
  Set general volume of speakers in office
trigger:
  - platform: time
    at: '09:00'
condition:
  - condition: time
    weekday:
      - mon
      - tue
      - wed
      - thu
      - fri
action:
  - service: media_player.volume_set
    data:
      volume_level: 0
    target:
      entity_id: media_player.study_room
mode: single