UnityWebRequestMultimedia to get AudioClip from API

What I'm trying to accomplish sounds fairly easy. I try to download an AudioClip from our own API using an UnityWebRequestMultimedia but the AudioClip which it retrieves seems to be null all the time.

This is the IEnumerator that runs in a Coroutine to load the AudioClip:

 private static IEnumerator loadAudio(DownloadJob<AudioClip> job)
 {
     UnityWebRequest webRequest = UnityWebRequestMultimedia.GetAudioClip(job.URL, AudioType.MPEG);
     
     yield return webRequest.SendWebRequest();
 
     if (!webRequest.isNetworkError && !webRequest.isHttpError)
     {
         DownloadHandlerAudioClip dlHandler = (DownloadHandlerAudioClip)webRequest.downloadHandler;
         if(dlHandler.isDone)
         {
             AudioClip audioClip = dlHandler.audioClip;
             
             if(audioClip != null)
             {
                 _audioCacheManager.Add(job.Key, audioClip);
                 job.Done(audioClip);
             }
             else
             {
                 job.Failed("Retrieved AudioClip is null.");
             }
         }
         else
         {
             job.Failed("The download process is not completely finished.");
         }
     }
     else
     {
         job.Failed(webRequest.error);
     }
 }

I can't spot any issues with this piece of code and I suspect that the WebRequest does not follow the API's redirect that points it to the audio file directly even though the RedirectLimit has not been changed and should still be on the default value of 32. When the call URL is opened in the browser it'll show an audioplayer without problems.

Any ideas?