Itext7 PDF merge - retain existing pdf styles

Question

When I merge multiple PDF documents together using iText. I am losing mouse hover effect on a link rectangular button. On mouse hover it is changing link button background colour and and text colour. How do I retain styles when merge?

I am using below code to merge the pdfs,

using (iText.Kernel.Pdf.PdfDocument d1 = new iText.Kernel.Pdf.PdfDocument(new 
iText.Kernel.Pdf.PdfReader(dsPath)))
{
            
    if (d1.GetNumberOfPages() != totalPdfPages)
    {
        totalPdfPages = d1.GetNumberOfPages();
    }

    merger.Merge(d1, 1, totalPdfPages);         
}