Cannot fully mute sound in zoom or FaceTime

I was trying to take a Zoom call in a room with someone else who is also on that same call on a different device. Zoom was absolutely not able to be silenced no matter what I did(their speakers were on). I used control center, the physical volume buttons, disconnected audio in zoom, and the volume would force itself back on no matter what I did.

Same issue proved to be in place for FaceTime.

help!