Updated to 2020.12 today,IKEA Symfonisk (Sonos) not playing mp3s anymore?

Hey folks, I just got this error by updating from 0.116.2 to 2020.12.
Playing short and long mp3s worked flawlessly with 0.116.2 (I’ve initially set this up in like Nov. 2020) but by updating to 2020.12 today, its not working anymore and in the logs I see the following:

Error on play_media with UPnP Error 701 received: Transition not available from 192.168.178.35
6:17:46 PM – Sonos (ERROR) - message first occurred at 6:17:45 PM and shows up 3 times

My automation looks as follows:

- id: '160322427'
  alias: Leave home
  description: Turns off lights, arms alarm, says goodbye.
  trigger:
  - device_id: 2592f657123123457ceb12011
    domain: deconz
    platform: device
    type: remote_button_short_press
    subtype: turn_on
  condition: []
  action:
  - service: alarm_control_panel.alarm_arm_away
    data:
      entity_id: alarm_control_panel.house_alarm
      code: 0000
    entity_id: alarm_control_panel.house_alarm
  - scene: scene.everything_off
  - service: media_player.volume_set
    data:
      entity_id: media_player.wohnzimmer
      volume_level: 0.3
    entity_id: media_player.wohnzimmer
  - service: media_player.play_media
    data:
      entity_id: media_player.wohnzimmer
      media_content_id: http://homeassistant.local:8123/local/lock.mp3
      media_content_type: music
  - service: notify.telegram
    data:
      title: Alarmanlage scharfgestellt
      message: Bis bald.

I am using HA on a Raspi in combination with IKEA Symfonisk.