Cannot OpenFileReadStreamAsync

[wnsan]

when I connect to FTP server it connect to high port (50000+) and stuck when OpenFileReadStreamAsync after login

            using (var ftpClient = new FtpClient(new FtpClientConfiguration
            {
                Host = PrPath,
                Username = ftpLogin,
                Password = ftpLogin,
                BaseDirectory = baseDirectory,
                SslProtocols = System.Security.Authentication.SslProtocols.None,
                
            }))
            {
                var fileinfo = new FileInfo(localpath);
                Console.WriteLine("login");
                await ftpClient.LoginAsync();
                Console.WriteLine("after login");
                byte[] existsData;
                try
                {
                    using (var readStream = await ftpClient.OpenFileReadStreamAsync(fileUpload))

                    {
                        Console.WriteLine("read remote");
                        existsData = ReadToEnd(readStream);
                        readStream.Dispose();
                        Console.WriteLine("after read remote");
                    }
                }
                catch (Exception readException)
                {
                    Console.WriteLine("first exception");
                    Console.WriteLine(readException.Message);
                    existsData = null;
                }
                using (var writeStream = await ftpClient.OpenFileWriteStreamAsync(fileUpload))
                {
                    Console.WriteLine("write stream");
                    var fileReadStream = fileinfo.OpenRead();
                    if (existsData != null)
                    {
                        var existReadStream = new MemoryStream(existsData);
                        await existReadStream.CopyToAsync(writeStream);
                    }
                    await fileReadStream.CopyToAsync(writeStream);
                    writeStream.Dispose();
                    fileReadStream.Dispose();
                    Console.WriteLine("after write stream");
                }
                ftpClient.Dispose();
                System.IO.File.Delete(localpath);

            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
        return 1;

it throw a connection attempt fail at XXX.XXX.XXX.XXX:51320 (high port) how can I fix this thank you