I have a MacBook Pro Sierra / version 12.12.6.
Everytime I import wave files 44K / 32 bit from Logic 8, everything sounds great. I can edit and master…etc. But after I close Audacity and shutdown my computer, then start up again the next day the wave files-song sounds gurgly and almost distorted.
I tested and tried many different wave files but it’s always the same experience.
Do you have Finder set to show you file name extensions? Finder > Preferences > [X] Show all Extensions…
If you have a WAV file, does it say something-something.wav, or just something-something?
You keep working on WAV files but your description of the problem is the poster child for damaged compressed file types.
Is the work damaged when played in QuickTime Player, iTunes or other player? Different computer?
Where did the work come from? Are you performing live?
If you are getting the work from “Somewhere Else,” you may have WAV versions of already badly compressed sound. In that case,you’d be fine inside Audacity but any editing or production you do may become damaged, seemingly “too soon” from what you were expecting.
Cut a ten second portion of the damage and post it here.
The point is to fix the gurgly sound. Changing the conditions between “Before” and “After” test clips isn’t helpful, particularly as you said you didn’t. The two clips are different and it has nothing to do with the second guitar. Somehow, the single guitar track went from mono (one track) to stereo (two tracks) and it would be good to know the step that created that change.
We have to build your system in our imaginations to diagnose problems. It’s difficult to hit a moving target.