conticreative,

Thank you for taking the time to so thoroughly present your post. It really helps understand you problem.

Does the sound continue even when the Audio is muted (in addition to all the instrument tracks)? I found myself wondering if maybe you have rendered an audio file of the back backing. If you have, such a file will automatically load when the song file is loaded and play when the song file is played.

Also, as a test, it would be worth clicking on "File | New" and create a short, brand new backing and then double check if this, too, has sound playing.

Your second point could also be due to a rendered audio file playing along. If not, check to see if you have frozen the tracks. If you have, unfreeze them and regenerate the song. That will align everything.

Hope this help,
Noel

MY SONGS...
Audiophile BIAB 2024