webgl hangs firefox when trying to use UnityWebRequestMultimedia.GetAudioClip

I am trying to download an audio clip from webgl. When I do it hangs firefox for about 10-20 seconds with an error that says something about a webpage is slowing down the browser do you want to stopit or wait . If I press stopit script the audio plays fine. If I say wait it never finishes. I've tried the code from the example and it does the same thing. In the editor this does not happen and the url loads almost instantly. The url is on the same server as the unity webgl.

Edit: I changed the code to this but still the same problem:

 public IEnumerator getAudioChannel1mp3(string url)
     {
         using (UnityWebRequest www = UnityWebRequestMultimedia.GetAudioClip(url, AudioType.MPEG)) {//AudioType.OGGVORBIS
             UnityWebRequestAsyncOperation async = www.SendWebRequest();
             yield return async;
 
             while (!async.isDone) {
                 Debug.Log("progress=" + async.progress);
                 yield return null;
             }
             if (async.webRequest.isNetworkError || async.webRequest.isHttpError) {
                 Debug.Log(www.error);
             } else {
                 AudioClip myClip = DownloadHandlerAudioClip.GetContent(async.webRequest);
                 GameObject.Find("pedro1").GetComponent<AudioSource>().clip = myClip;
                 GameObject.Find("pedro1").GetComponent<AudioSource>().Play();
                 testingaudio = true;
             }
         }
     }

 public IEnumerator getAudioChannel1mp3(string url)
 {
     using (UnityWebRequest www = UnityWebRequestMultimedia.GetAudioClip(url, AudioType.MPEG)) {//AudioType.OGGVORBIS

         yield return www.SendWebRequest();

         while (!www.isDone) {
             Debug.Log("progress=" + www.downloadProgress);
         }
         if (www.isDone) {

         AudioClip myClip = DownloadHandlerAudioClip.GetContent(www);
             GameObject.Find("pedro1").GetComponent<AudioSource>().clip = myClip;
             GameObject.Find("pedro1").GetComponent<AudioSource>().Play();
             testingaudio = true;
         }
     }
 }