Mute button should be visible/useable when

Mute button should be visible/useable when an external mobile user places the call on Hold

When an external mobile user places the call on Hold the Mute button is not visible. I can not activate Mute while on hold. That bothers me, as I want to do other things and not have the microphone open while waiting. For me it is a data privacy issue, as I can never be sure when the call continues and what the other person on the line could listen to (of what I am doing while on Hold).

A visible and useable Mute button while a call is on Hold would be appreciated.