Whisper API- Issue with call recording m4a File

I am creating a simple website that takes in phone recording and transcribes them with WhisperAI API. I ran into this peculiar trouble where m4a audio files of phone recordings are not recognized as m4a by WhisperAI
error 400 “Invalid file format. Supported formats: [‘m4a’, ‘mp3’, ‘webm’, ‘mp4’, ‘mpga’, ‘wav’, ‘mpeg’]”

Stranger yet, if I convert the file to mp4 (or any other files) and convert it back to m4a, it then recognizes it as a valid file also if I downloaded an audio directly from google in m4a format I am getting the response.

I’m not sure how to proceed from here so I would really appreciate any sort of feedbacks. Thanks in advance!

Running into this too, did you ever figure it out?