Problems downloading big size files (20 GB) from the API .NET

It varies. I did some more testing and it also happens with smaller files. I was downloading a file of 3.48 GB but just 1.75 GB were downloaded. This happened in exaclty 15 minutes without any error showing. This the complete method code.

      private async Task<int> Run()
        {
            DropboxCertHelper.InitializeCertPinning();

            

            // Specify socket level timeout which decides maximum waiting time when no bytes are
            // received by the socket.
            var httpClient = new System.Net.Http.HttpClient(new WebRequestHandler { ReadWriteTimeout = 100 * 10000000 })
            {
                // Specify request level timeout which decides maximum time that can be spent on
                // download/upload files.
                Timeout = TimeSpan.FromHours(10)
            };

            try
            {
                var config = new DropboxClientConfig("SubidaBacks")
                {
                    HttpClient = httpClient
                };

                var dbx = new DropboxClient("************", config);

                var nbackups = 0;
                var ListaBaks = new List<string>();
               

                using (dbx)
                {


                    var full = await dbx.Users.GetCurrentAccountAsync();


                    foreach (var folder in Folders.Split(';'))
                    {
                        var listOfFolders = await dbx.Files.ListFolderAsync(folder, true);

                        FolderMetadata dropboxFolderInfo = new FolderMetadata();
                        FileMetadata dropboxFileInfo = new FileMetadata();
                        Int64 local, cloud;



                        foreach (var item in listOfFolders.Entries)
                        {
                            try
                            {
                                if (item.IsFile)
                                {

                                    foreach (var fecha in Dates())
                                    {

                                        if (item.Name.ToString().Contains(fecha))
                                        {

                                            var localname = localFilePath + "\\" + item.Name;

                                            if (!File.Exists(localname))
                                            {
                                                dropboxFileInfo = (FileMetadata)item;
                                                var response = await dbx.Files.DownloadAsync(dropboxFileInfo.PathLower.ToString());
                                                ulong fileSize = response.Response.Size;
                                                const int bufferSize = 1024 * 1024;

                                                var buffer = new byte[bufferSize];

                                                Console.WriteLine("Descargando " + dropboxFileInfo.Name.ToString() + "...");

                                                using (var stream = await response.GetContentAsStreamAsync())
                                                {
                                                    using (var file = new FileStream(localname, FileMode.OpenOrCreate))
                                                    {
                                                        var length = stream.Read(buffer, 0, bufferSize);

                                                        while (length > 0)
                                                        {
                                                            file.Write(buffer, 0, length);
                                                            var percentage = 100 * (ulong)file.Length / fileSize;
                                                            // Update progress bar with the percentage.
                                                            // progressBar.Value = (int)percentage
                                                            Console.WriteLine(percentage.ToString()+"% - "+ dropboxFileInfo.Name.ToString() +" - " + DateTime.Now.ToString());

                                                            length = stream.Read(buffer, 0, bufferSize);
                                                        }

                                                         local = Convert.ToInt64(file.Length);
                                                         cloud = Convert.ToInt64(dropboxFileInfo.Size);

                                                       

                                                    }


                                                }

                                                if (local == cloud)
                                                {
                                                    ListaBaks.Append(item.PathLower.ToString());
                                                    nbackups = nbackups + 1;
                                                    Console.WriteLine("Descargado");
                                                    
                                                }
                                                else
                                                {
                                                    File.Delete(localname);
                                                    Console.WriteLine("Error al descargar");

                                                }

                                                
                                            }
                                        }
                                    }
                                }
                            }
                            catch (Exception ex)
                            {
                                Console.WriteLine(ex.Message);
                            }
                        }
                    }


                }

                // Correo.EnvioCorreo(nbackups.ToString(), string.Join("\n", ListaBaks));

            }
            catch (HttpException e)
            {
                Console.WriteLine("Exception reported from RPC layer");
                Console.WriteLine("    Status code: {0}", e.StatusCode);
                Console.WriteLine("    Message    : {0}", e.Message);
                if (e.RequestUri != null)
                {
                    Console.WriteLine("    Request uri: {0}", e.RequestUri);
                }
            }

            return 0;
        }