Trying to configure Multi Room Audio Player zone, you can notice that your sound device is running in stereo instead of 5.1 or 7.1 channel mode.
Please start Multi Room Audio Player and go to the Tools menu, click on the Settings and select Remote tab. Please turn on “Enable remote control” checkbox. You can’t specify an address, this is your computer local address, but you can change a port. After changing the Port, please click “Restart” button.