A DESCRIPTION OF THE PROBLEM :
A html containing 3 elements (A and B visible, C hidden) is shown within a WebView. The element A triggers the show/hide of the element C. When C is visible: C should be in the foreground and B in the background. However, the scrollbar of B is displayed above C. Additionally, the scrollbar partially covers the content of B.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Download the file example.html from https://hexmet-my.sharepoint.com/:f:/g/personal/andreea_plocon_hexagon_com/EqtHyTs-zCtDumkC_pJo5OoBrher9pbRPKZSSEBn7fjUYA. Run the provided source code to display example.html within a WebView.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The file chromeScrollbarBelowElement.PNG from https://hexmet-my.sharepoint.com/:f:/g/personal/andreea_plocon_hexagon_com/EqtHyTs-zCtDumkC_pJo5OoBrher9pbRPKZSSEBn7fjUYA shows the right behaviour when displaying example.html in Chrome.
ACTUAL -
The file jfxScrollbarAboveElement.PNG from https://hexmet-my.sharepoint.com/:f:/g/personal/andreea_plocon_hexagon_com/EqtHyTs-zCtDumkC_pJo5OoBrher9pbRPKZSSEBn7fjUYA shows the JFX behaviour when displaying example.html in a WebView.

---------- BEGIN SOURCE ----------
public class WebViewScrollBarsIssue extends Application {

@Override
public void start(Stage stage) {
WebView webview = new WebView();
webview.getEngine().load("file:///C:/example.html");

stage.setScene(new Scene(webview));
stage.show();
}

public static void main(String[] args) {
launch(args);
}
}
---------- END SOURCE ----------