In my Ableton Live 10 project right now, I have both midi and audio tracks. When I press the solo button on my midi tracks it behaves as I expect - the solo'd track is audible and all the others are muted.
When I press 'solo' on one of my audio tracks, however, I hear nothing - all of the other tracks are muted but the track in question is muted too.
How can I hear the output of just one of my audio tracks?
If it matters, the output of the midi tracks is routed to Master, and the audio tracks are routed to a mix of A and B sends, which then route to Master.