I'm encountering the same bug. I suspect it's related to the state of the AudioContext. From what I've observed, when first entering the page, the state of AudioContext is suspended, and calling resume() within a click event fails to restore it. If I first call suspend() followed by resume() in the developer tools console, the following error message appears. So far, I haven't found a workaround—please share one if you have it.
error message:
InvalidStateError: Failed to start the audio device
Topic:
Safari & Web
SubTopic:
General