Multicam using an audio track I switched to stereo, cuts disable sound

I changed the main audio track to stereo before using it in a multicam sequence. Now when I make a cut, the audio turns off after the cut. This did not happen when the track was in mono. How can I fix this?

Also, how can I change a whole edited sequence to stereo. I know how to do it to the audio track before editing, but what if I've finished editing?

Thanks in advance!!