Audio cleaner
Lift the quiet parts. Cut the dead air.
Normalize a voice note and trim the silence on either end. You get a WAV back. A video belongs on Separate, which only pulls the soundtrack off.
Fixes
Leave both off to just rewrite it as a WAV. Some files play through once if the browser can't decode them directly.
Drop audioMP3, WAV, M4A, OGG, or FLAC