Periodically, at a random moment, the sound disappears during operation. It turned out that the mixer is no longer defined as an audio interface. The causes and triggers are unclear, only once did it look like static electricity was the cause, but only once, in other cases it looked as if it was causeless.
P.S. At first, it was solved by restarting the mixer every time. Then I found a faster way – switching the sampling rate.
P.S.S. Unfortunately, I didn’t pay enough attention to it at first, but I had to think about it after the incident at the concert.