Sonos plays TTS messages even thought it's muted and volume Level 0

Hey guys,
I have noticed that my Sonos Era 100 speakers which I use for my doorbell as well as for my automation messages (like "please close the Windows" via TTS Google translate) do play the the messages still independed of if I mute the speakers or not. The volume Level does has an effect but when I set it to 0 it is still hearable even thought very quitely.

The doorbell (playing a file) is working as intended.

The speakers are not grouped and I have not Set any Sound enhancements in the Sonos App.

Here is my automation example:

action: tts.speak metadata: {} data: cache: true message: please close window media_player_entity_id: media_player.sonos_OG target: entity_id: tts.google_de_de enabled: true

Any idea whats the Problem and how I can fix it?

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OK have done it

Hm has/had nobody the same issue? This usecase shouldnt be so rare or?