Element not found when executing findElement in Selenium

I'm trying to fill in multiple forms that come after each other, all the forms get filled swiftly with no errors because I make sure to add

WebDriverWait wait = new WebDriverWait(driver, 20);
wait.until(ExpectedConditions.elementToBeClickable(By.xpath("")));

before doing anything on a new page, and I know I'm on the correct page.

On the last form, I encounter this error :

Exception in thread "main" org.openqa.selenium.NoSuchElementException: Unable to locate element: //*[@id="formtovalidate"]/fieldset[1]/div/label/input For documentation on this error, please visit: https://www.seleniumhq.org/exceptions/no_such_element.html

So I went to check on the browser by taking a screenshot and the browser is on the correct page with the correct form, I also checked the xpath values and even tried other attributes.. nothing seemed to work.

So I went ahead and printed out the PageSource which showed a totally different page (not the previous page), I also noticed the this page flashed for a second before the final form appeared.

I also tried driver.navigate().refresh() but that didn't work. I kept searching and looking but nothing appeared. I also changed browsers, that did nothing..

This is the method I'm trying to execute:

private void method() {

WebDriverWait wait = new WebDriverWait(driver, 20);
wait.until(ExpectedConditions.elementToBeClickable(By.xpath("//*[@id=\"formtovalidate\"]/fieldset[1]/div/label/input")));
driver.findElement(By.xpath("//*[@id=\"formtovalidate\"]/fieldset[1]/div/label/input")).sendKeys(email); }

Update

Here's the form screenshot:

Here's the execution results:

Code:

String body_text = driver.findElement(By.tagName("body")).getText();
System.out.println(body_text);

Result: The form but in text

Code:

String body_innerHTML = driver.findElement(By.tagName("body")).getAttribute("innerHTML");
System.out.println(body_innerHTML);

Result: A different page :(

<zendesk-ticketing-form base-url="https://www.runescape.com/a=870/c=K0aO9WO69EI" css-cachebust="129" sitekey="6Lcsv3oUAAAAAGFhlKrkRb029OHio098bbeyi_Hv" grecaptcha="" has-valid-session="true" weblogin-url="https://secure.runescape.com/m=weblogin/a=870/c=K0aO9WO69EI/loginform?mod=www&amp;ssl=1&amp;dest=zendesk/support-form?form=360000065898">
<div class="x-display-none ie-error-display" data-js-ie-error="">
    <section class="c-article">
        <div class="c-article__content">
            <h1>Error: Unsupported Browser</h1>
            <p>
                We do not support your web browser. Please use a supported web browser by choosing one below.
                <br>
                <a href="https://www.mozilla.org/firefox/" target="_blank" rel="noopener">FireFox</a>
                <br>
                <a href="https://www.google.com/chrome/" target="_blank" rel="noopener">Chrome</a>
            </p>
        </div>
    </section>
</div>

Code:

 String pagesource = driver.getPageSource();
        System.out.println(pagesource);

Result: Same as the previous one.. different page..

Firefox Page Source: https://pastebin.com/Kv15V2SK

Firefox Inspect Element of the page screenshot: http://prntscr.com/qvi6hc

This is weird, as the page source is different to the form!