[Selenium] Screenshot von Google ReCaptcha falsche position

private bool SolveCaptcha(FirefoxDriver webdriver)
        {
            var currentFrame = driver.CurrentWindowHandle;
            var iframe = driver.FindElementsByTagName("iframe");
            var el = iframe[0];
            driver.SwitchTo().Frame(el);
            driver.FindElementById("recaptcha-anchor").Click();
            Thread.Sleep(1000);
            driver.SwitchTo().DefaultContent();
            iframe = driver.FindElementsByTagName("iframe");
            el = iframe[2];
            driver.SwitchTo().Frame(el);
            Thread.Sleep(1000);
            var text = driver.FindElementByClassName("rc-imageselect-desc-wrapper").Text;

            if (File.Exists("captcha.png"))
            {
                File.Delete("captcha.png");
            }

            var arrScreen = webdriver.GetScreenshot().AsByteArray;
            using (var screen = new MemoryStream(arrScreen))
            {
                var bmpScreen = new Bitmap(screen);
                //var captchas = webdriver.FindElementsByClassName("captcha");
                //var element = captchas.FirstOrDefault(item => item.GetAttribute("class") == "captcha");


                var captcha = webdriver.FindElementById("rc-imageselect");

                var rectangle = new Rectangle(captcha.Location, captcha.Size);
                Image imgCap = bmpScreen.Clone(rectangle, bmpScreen.PixelFormat);
                imgCap.Save("captcha.png");
                using (var msCaptcha = new MemoryStream())
                {
                    imgCap.Save(msCaptcha, ImageFormat.Png);
                }
            }

            return false; // noch keine funktion
        }