Logitech Touch won't mute to silence

One of my end points is a Logitech Touch.

I have noticed that when I try to Mute it from within Roon the X appears but I can still hear music.

If I take the volume slider to 0 (without Mute) I get that same low level of audio perfectly listenable, so Mute is not cutting off the audio, it is just taking it to the lowest level.

Is there a way to re-calibrate “0”/“X”?

Thanks in advance - Terry