✳ AUDIO DIAGNOSE
Diagnose: no sound plays back on the destination
Dynamic diagnostic state for this problem. Choose a file to run the diagnostic tree; the page rerenders with ranked causes and recommended fixes.
Direct answer
Two most likely causes: the player was muted (autoplay is silent by default on many feeds), or the export step dropped the audio stream. Open the original locally first; if the original has sound, the conversion or the upload lost it.
Run the diagnostic tree
The tree combines this problem's static cause ranking with the values the diagnostic engine reads from your file.