I’m importing a stereo m4a file, and Audacity repeats the left channel on the right channel. I have installed the FFmpeg Import/Export Library as recommended in:
The file was generated in MATLAB. Left and right channels are very different. I have saved it in wav and m4a formats. Other apps play both channels correctly for both formats. Audacity imports the wav file correctly but in the m4a file the left channel gets duplicated replacing the right channel.