Magnifi mini - no sound after a volume change

Hi,
My Magnifi mini is connected to the TV with ARC connection, the TV is connected to Nvidia Shield Pro streamer. TV and Shield are set to use CEC.
Now, when I change a volume the sound disappears. It doesn't matter how I do it, via TV volume, or Polk remote, or Shield remote, the result remains the same.
Please assist in solving the issue

Answers