Here are some steps to reproduce:
1/ Start new game
2/ Activate "Move your shuttle"
3/ When mode timer is about to expire, launch the ball up the shuttle ramp
This kicks off the shuttle animation (before you're instructed to hit the heart beat ramp to lite locks). During this animation the "Move your shuttle" mode completes and music stops.
Music doesn't come back until the next ball.
I'm not sure if this can be reproduced with the same steps for other wheel modes, but certainly a mode ending during the shuttle prep animation causes the music to cut.
I wanted to log this here in case we're lucky enough to see a v1.20 - or hopefully the source is released for the community to continue to patch
