Apparently, it is the subfolder path for the homepage property that is doing it.
Not sure if this is a bug or what but when using the homepage property with a subfolder path the audio file shows up as 206 Partial Content in the network tab and the Content-Type of the audio files are Content-Type: text/html; charset=UTF-8 which is not correct.
With subfolder path for the homepage property:
Without subfolder path for the homepage property:
The MIME type of the actual source file in the DOM is correct.
I’m guessing this issue is specific to create-react-app but I didn’t really look into it much.

