My audio Settings have changed to Roku Stick and the Mute button is dimmed. I cannot use the sound on my Macbook

With the latest update my audio is gone and the sound device has been replaced by Roku Stick. I have searched the web for a solution which lead me right back to the community. Please help.

I have read the suggestions but "AirPlay" is not showing up anywhere on my device. So I am complete loss as to what changed or why Roku Stick is my audio device. Noisome at best.