CowboyToadTeam claims that audio doesn't work in preview. Browser autoplay restriction should not affect the preview. Also, if this was related to autoplay restriction, playing audio in "On Tap" event should have fixed the issue, but it didn't.
CowboyToadTeam Have you tried other audio files? Maybe there is a problem with this particular track. Try converting it to other formats, like mp3 or wav. Also, try running the project in Debug mode and check if Audio object is playing this track or not.