Selenium FluentWait and element not visible exception

i'm trying to use FluentWait instead of sleep and this is my first practice. First of all and most importantly am i doing it right at all ? Secondly i got through two elements so i thought it kind of works (PaymentMethod button and CheckOut button). Before i implemented FluentWait it wouldn't find them. And finally it won't find the third(backToDesktop button) element. Keeps throwing Element not visible, although i added the wait.ignore(ElementNotVisibleExcecption.class).

FluentWait<WebDriver> wait = new FluentWait<WebDriver>(login.getDriver());
    wait.withTimeout(5, TimeUnit.SECONDS);
    wait.pollingEvery(250, TimeUnit.MILLISECONDS);
    wait.ignoring(NoSuchElementException.class);
    wait.ignoring(ElementNotVisibleException.class);

WebElement paymentMethod = wait.until(new Function<WebDriver, WebElement>() {
        public WebElement apply(WebDriver driver) {
            return login.getDriver().findElement(By.xpath("//*[@id='paymentMethodHolder']/div[1]/div[1]/button"));
        }
    });
    paymentMethod.click();
    System.out.println("FOUND PAYMENTMETHOD BUTTON");

    WebElement checkOut = wait.until(new Function<WebDriver, WebElement>() {
        public WebElement apply(WebDriver driver) {
            return login.getDriver().findElement(By.xpath("//*[@id='checout-footer-buttons']/button[2]"));
        }
    });
    checkOut .click();
    System.out.println("FOUND KINNITA BUTTON");

    WebElement backToDesktop= wait.until(new Function<WebDriver, WebElement>() {
        public WebElement apply(WebDriver driver) {
            return login.getDriver().findElement(By.className("modal-button-text"));
        }
    });
    backToDesktop.click();

    System.out.println("FOUND BACKTODESKTOP BUTTON");