Ring indoor cameras allowing shared users to activate audio once.

My indoor Ring Cams are shared to some users and audio is toggled to OFF. When shared users go onto the cameras there is an option to activate audio once. This means shared users can click on the speaker icon 'activate audio' each time they view the camera live.How do I stop this? I want them to be blocked from this as they are not the owner of the camera. I just set up some cameras for a family member and these do not allow shared users to turn on audio as the 'activate audio once'option is not available. I can't see a difference in the setting and setup in either instance. Why is this? I need a solution please.