When I create TextHiglightAnnotation by programmatically then it make difference from the default pdfjs highlight tool.
Here is my code.
const highlight = new Annotations.TextHighlightAnnotation();
highlight.Author = annot.Author;
highlight.Hidden = false;
highlight.Quads = annot.Quads;
highlight.StrokeColor = new Annotations.Color(255, 176, 176, 1);
highlight.PageNumber = annot.getPageNumber();
highlight.Locked = false;
highlight.setCustomData("trn-custom-data", "Test Data");
highlight.Subject = 'Highlight';
annotManager.addAnnotation(highlight, true);
annotManager.drawAnnotations(1);
Output:
