Stamp Annotation added at wrong place

Question

Using below code when we add Stamp Annotation on PDF page, it will add that stamp at random location for some files.

BufferedImage bufferedImage = getImage();
PDImageXObject image = JPEGFactory.createFromImage(pdDocument, bufferedImage)
PDAnnotationRubberStamp rubberStamp = new PDAnnotationRubberStamp();
rubberStamp.setRectangle(new PDRectangle(x, y,  width, height));
rubberStamp.setName(Name);
PDFormXObject form = new PDFormXObject(pdDocument);
form.setMatrix(AffineTransform.getRotateInstance(Math.toRadians(rotation)));
form.setBBox(new PDRectangle(x, y,  width, height));
form.setResources(new PDResources());
PDAppearanceStream myDic = new PDAppearanceStream(form.getCOSObject());
PDPageContentStream pageContentStream = new PDPageContentStream(pdDocument, myDic);
pageContentStream.drawImage(image, x, y, width, height);
pageContentStream.close();
PDAppearanceDictionary appearance = new PDAppearanceDictionary(new COSDictionary());
appearance.setNormalAppearance(myDic);
rubberStamp.setAppearance(appearance);
annotations.add(rubberStamp);

For example, for some files x coordinate 0.0 considers right side of page and for some files it will be bottom.