Java Selenium没有包含正确xpath下拉列表的此类元素异常

我有一个测试用例中的代码，它工作正常，但从一天到下一天它都停止工作，我不明白为什么

   @Test
    public void addAreaToSurvey() throws InterruptedException {
        SurveyPage surveyPage = basePageNavigation();
        Thread.sleep(2000);
        int surveysNum = surveyPage.getRowsTable().size();
        int rowTable = (int)(Math.random() * (surveysNum - 1 + 1) + 1);
        int numberOfLabels = surveyPage.getNumberOfLabels(rowTable).size();
        surveyPage.getAssignAreaButton(rowTable).click();
        Thread.sleep(5000);
        new WebDriverWait(surveyPage.driver, 20).until(ExpectedConditions.presenceOfElementLocated(By.xpath("//body/div[3]/div[3]/div[1]/ul[1]")));
        int RowsDropdownNum = surveyPage.getRowsLabelsAreaDropdown().size();
        int random_int2 = (int)(Math.random() * (RowsDropdownNum - 1 + 1) + 1);
        String nameAreaToAdd = surveyPage.getLabelsAreaDropdown(random_int2).getText();
        surveyPage.getLabelsAreaDropdown(random_int2).click();
        Thread.sleep(2000);
        int rowNum2 = surveyPage.getRowsLabelsAreaDropdown().size();
        int random_int3 = (int)(Math.random() * (rowNum2 - 1 + 1) + 1);
        String nameBranchToAdd = surveyPage.getLabelsAreaDropdown(random_int3).getText();
        surveyPage.getLabelsAreaDropdown(random_int3).click();
        Actions action = new Actions(surveyPage.driver); //click outside dropdown to close it

        if(rowTable > 8){
            action.moveByOffset(200,500).click().perform();
        }else{
            action.moveByOffset(200,45).click().perform();
        }
        Thread.sleep(1000);
        Assert.assertTrue(numberOfLabels == (surveyPage.getNumberOfLabels(rowTable).size() - 1));
        Assert.assertTrue(surveyPage.getAreaLabelInTable(rowTable, numberOfLabels).getText().equals(nameAreaToAdd));
        Assert.assertTrue(surveyPage.getBranchLabelInTable(rowTable, numberOfLabels).getText().equals(nameBranchToAdd));
    }

错误发生在以下行中： int RowsDropdownNum=surveyPage.getRowsLabelsAreaDropdown（）.size（）

public List getRowsLabelsReadropdown（）{return driver.findElements（RowsLabelsReadropdown）；}
最后一个private By rowsLabelsAreaDropdown=By.xpath（“//body/div[3]/div[3]/div[1]/ul[1]/div”）；

我已经研究了好几天，但我找不到任何东西，下拉列表是可见的，正确的定位器，我等待它加载，没有iframe。 有人知道会是什么吗

    public List<WebElement> getRowsLabelsAreaDropdown(){ return driver.findElements(rowsLabelsAreaDropdown); }

final  private By rowsLabelsAreaDropdown = By.xpath("//body/div[3]/div[3]/div[1]/ul[1]/div");