Garage Band tracks stuck mute

Hi, returned to a Garage Band project after months away and opened it in an updated (latest) version on Ventura 13.1. Added a track (AIFF file from Music). When I play the project back, the only track that outputs audio is the new track, even though it's indicating muted in the left margin (a diagonal line through the little speaker icon). Trouble is, all of the other tracks are muted and none of them output audio when played -- unless soloed! Clicking on the crossed-out-speaker on each track is futile, the icon just doesn't change. None of this was (knowingly) done by me! How do I hear my mix? Any tips?