1. How are you exporting? Did you try to "bounce" your project? Either by pressing the "Bnc"- button on the stereo out channel strip or choosing "File > Bounce > Project or Section".
Does bouncing work?
2. To make sure your issue is not instrument related (in fact it's a Track Stack, a combination of two instruments and it doesn't consistently play the same note with the same instrument on my computer !?! ), create a New Software Instrument Track and choose something simple like a vibraphone (not "vibraphone and bass") or an acoustic piano. Drag the region onto the new track. Can you hear everything now?
Try a bounce, can you still hear everything now?
3. If you still can't hear your track, open the Event List by pressing CMD+0, then select the region. Inspect CC or midi information other than midi notes. Your screenshot indicates a lot of them by showing "#". Maybe they are causing your problem?
BTW, the "green light on the mixer" you mentioned might be an automation indicator:
https://support.apple.com/guide/logicpro/show-automation-curves-lgcpb1a3f099/mac
"(...) For Read mode, however, the button and text color display the current state of automation and if there is automation data present:
Green text on a gray background = automation is on but there is no existing automation data to display
White text on a green background = automation is on and there is existing automation data to display (...) "
