I see what’s going on now. In the “Configure Multitrack Playback” Helix has 4 output pairs. 1,2 3,4 5,6 7 and 8. Only audio on 1,2 is playing. The audio tracks on 3,4 5,6 7,8 play but cannot hear them. I don’t know how this happened, maybe Ableton changed something but these output are fixed and I don’t see how to change the routing. The documentation says I can but how do I do that? I tried Audio Midi setup but no success. This was working until I decided to experiment.