Can’t unmute watch

when I receive a phone call on my watch, I cannot hear the person unless I put the watch up against my ear. The microphone icon has a line thru it and if I press it, the icon is highlighted but still has the line and I cannot hear. The volume icon also has a line thru it. I’ve checked the mute button, airplane mode and and they are off. The volume control is all the way up. Can someone please help????