(container format) (container element) (container value) does not match (content format) (content element) (content value)
ISO IEC 23003-3 (USAC):numOutChannels: "determines the number of audio channels for which a specific loudspeaker position shall be associated"
ISO IEC 23003-4 (DRC):baseChannelCount: "Number of channels in the base layout / original audio input"
ISO IEC 23003-3:
Fix the encoder in order to set baseChannelCount value to numOutChannels value, then reencode the content.