Just in case anyone reads this in the future and none of the above options works, I had the orginal problem the poster had and I couldn’t get audio tracks 1 and 2(viewer side) to patch into audio tracks 1 and 2 output unless there was already audio on tracks one and two output. For some reason, when I went from mono on output audio tracks 1 and 2 back to stereo, had to clean up some audio so I split them up, whalla…I got the patches back allowing me to output where there was not audio already on tracks 1 and 2.
So, if you deselect a stereo pair of tracks and modify – uncheck stereo pair, after cleaning up the audio on each respective tracks, make sure to re-link them under modify.