ScreenShot taken isn’t of what’s showing in the screen, but rather that of the header until a page size

When I try to take a screenshot, I added a scroll so that it can take a significant screenshot and not only the header. Right now, the picture is still taken from the header/top of the page.
Am I doing something wrong?
Screenshot method :
public void ScreenShot() {
JavascriptExecutor js = (JavascriptExecutor) driver;
js.executeScript(“scroll(0,450);”);
DateTimeFormatter dtf = DateTimeFormatter.ofPattern(“yyyy-MM-dd HH_mm_ss”);
LocalDateTime now = LocalDateTime.now();
String destDir = System.getProperty(“user.dir”) + “/” + “test-output/ScreenShots”;
String FileName = “SoftAssertScreenshot_” + dtf.format(now) + “.png”;
String DestFile = destDir + “/” + FileName;
File file = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);
File ScreenshotName = new File(DestFile);
try {
FileUtils.copyFile(file, ScreenshotName);
} catch (IOException e) {
e.printStackTrace();
}
Reporter.log(“</br><font color=’#73a9d0′>***************Screen Of the error****************</font>”);
Reporter.log(“</br><img id=’ErrorResult’ src='” + DestFile + “‘ style=’width:600px’/>”);
}

Unable to locate element: {“method”:”xpath”,”selector”:”//*[@id=”root”]/div[1]/div/main/div/section/div/section/div/div/ul/li[1]/a”}

The chrome browser version is Version 115.0.5790.171 and downloaded chrome driver version is 114
[![enter image description here][1]][1]
as driver version 115 is not available.
I’m using the x-path and checked the x-path is correct or not in developer tool under console section it is correct. Even tried absolute path given by Automation Tester but still getting as No such element is found
[![enter image description here][2]][2]
[![enter image description here][3]][3]
This x-path is getting due to chrome browser version is 115 and chrome driver version is 114 using due to unavailable.
Could someone please help me
[1]: https://i.stack.imgur.com/RnSVN.png
[2]: https://i.stack.imgur.com/ydrhs.png
[3]: https://i.stack.imgur.com/hXedl.png

What are very localized whitebox tests called?

Assumptions, imagine we are selling a software API:

a “system test” verifies that a system works by calling it’s public interface e.g. assert(init()==true) or assert(MY_PI > 2 && MY_PI <= 10)
a set of “unit tests” verifies the public interface of implementation details (assuming OOP: all public methods and fields) does what is expected
an “integration test” is something in between and is not really important for the question.

What I wonder is what is the term/s for more localized whitebox tests :

private methods(and if You cluster that with “unit”, what about lambdas?)
assert()*s peppered inside methods/functions.

* – referring to C++ asserts which compile to no operation in release code; not python asserts which are beautiful ifs