Due to some programming issues that was inhibiting the way Extron handled muting, campus IT updated the software and had to reconfigure their behavior somewhat.
To turn on Video Mute: Press the Video Mute button
To turn off Video Mute: Press the Display ON button
To turn on Audio Mute: Press the Audio Mute button
To turn off Audio Mute: Press the Volume UP button
Essentially the top and bottom buttons on the left and right control the “muting”.