I'm sorry to hear that... was it the one with the light box? Our composer ran into the same issue where they fell into the water at the same time as the box, and wound up getting stuck on top of the map. There's a zone under the map to account for falling through, but unfortunately we never imagined the opposite happening haha.
As for the audio sliders, I'm fairly sure the UI doesn't release input when you close the menu, so moving left/right will shift the sliders; the only way I managed to get it to stop in the released build was to open the fullscreen dropdown and pick something.
We really appreciate that you played that far despite all the challenges :)