According to this article, the mute button is only active during the two minutes of "speechifying." After that there is a period of time when both candidates may speak.
To me, this is just enforcing common courtesy. You should have enough self control to not speak over the other person while they are making their point.
Among good people you’d be right. The left has proven time and again they are not good people. There is always an ulterior motive and this one is clear. Shut Trump down and elevate Biden.