Thank you for the detailed explanation Robert! It sounds like your tracks are being routed to separate outputs which is why the style mix or bass track are the only ones heard. They are likely being routed to outputs (St->1-2) which are the only active output channels. Luckily there is a quick fix for this.

1. Go to Preferences->Rendering and disable the option to "Separate Audio Output Channels" if it is not already disabled. Now future generations should automatically route all track outputs to (St->1-2).

2. To avoid having to regenerate, you can also manually change the output channels for each generated track. Click on the light-blue audio channels label to the far right of each track. Change the output channels to Stereo Out->1-2 (St->1-2).

Hope this helps!