I've also tried .mp4 files. Same issue.
Yes the audio is on. There is audio on all of the slides, and they play fine. It's only the video audio that doesn't work when publishing.
Appreciate your input.
Can you please create a blank project with that video and then try to reproduce the issue ?
Can you please check the published output on any other machine ?
Are you facing this issue with any particular video file ?
Thanks and Regards