Webclient returning download progress as 0 - xamarin

Question

I have written a helper class to download file from a server using the webclient class. The code was working fine until a while ago. All of a sudden the code is not working, the download progress is always 0 and toal bytes to receive is always -1. The download works fine but the issue is only with the actual progress change. The download progress remains zero from start to the end of download process, even the total bytes to receive remain as -1.
Please find the sample code mentioned below.
public class FileDownloader
{
private string _zipFilePath;
private string _destinationPath;
private int _productId;
public Action<int,int> progressListener;
private WebClient _client;
public void Download(string cloudPath, string localPath,int id)
{
_productId = id;
_zipFilePath = localPath +id+ ".zip";
_destinationPath = localPath + id;
if (!Directory.Exists(localPath))
{
Directory.CreateDirectory(localPath);
}
_client = new WebClient();
if (cloudPath != "")
{
Uri uri = new Uri(cloudPath);
_client.DownloadFileCompleted += new AsyncCompletedEventHandler(DownloadFileCallback);
_client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(DownloadProgressCallback);
_client.DownloadFileAsync(uri, _zipFilePath);
}else
{
progressListener?.Invoke(_productId, -1);
}
}
public void DownloadProgressCallback(object sender, DownloadProgressChangedEventArgs e)
{
if(e.ProgressPercentage != 100)
progressListener?.Invoke(_productId, e.ProgressPercentage);
}
public void CancelDownload()
{
_client.CancelAsync();
}
public void DownloadFileCallback(object sender, AsyncCompletedEventArgs e)
{
if (e.Cancelled == false && e.Error == null)
{
//UnzipContent(_destinationPath,_zipFilePath);
UnzipHandler unzipHandler = new UnzipHandler(_destinationPath, _zipFilePath,new UnzipCompletionCallback(UnzippedCourse));
Thread thread = new Thread(new ThreadStart(unzipHandler.UnzipContent));
thread.Start();
}
else
{
DeleteZip(_zipFilePath);
progressListener?.Invoke(_productId, -1);
}
}
private void DeleteZip(string zipPath)
{
if (File.Exists(zipPath))
{
File.Delete(zipPath);
}
}
public void UnzippedCourse(bool status)
{
DeleteZip(_zipFilePath);
if(status)
progressListener?.Invoke(_productId, 100);
else
progressListener?.Invoke(_productId, -1);
}
public delegate void UnzipCompletionCallback(bool result);
}