iText 7 : This pdf document might not be displayed correctly Firefox

I am running into strange issue with generated pdf's from iText7. The generated pdf's are opening properly in Adobe reader and Chrome browser. But the same pdf is opening partially in the Firefox browser. I am getting the below message in Firefox. The strange thing is other pdf, which are not generated via iText are properly rendering in firefox.

Java code

public static byte[] createPdf(List<String> htmlPages, PageSize pageSize, boolean rotate) throws IOException {

    ConverterProperties properties = new ConverterProperties();

    // Register classpath protocol handler to be able to load HTML resources from class patch
    org.apache.catalina.webresources.TomcatURLStreamHandlerFactory.register();
    properties.setBaseUri("classpath:/");
    // properties.setBaseUri(baseUri);

    FontProvider fontProvider = new DefaultFontProvider(true,false,false);
    properties.setFontProvider(fontProvider);

    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    PdfDocument pdf = new PdfDocument(new PdfWriter(byteArrayOutputStream));
    PdfMerger merger = new PdfMerger(pdf);

    for (String htmlPage : htmlPages) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        PdfDocument temp = new PdfDocument(new PdfWriter(baos));
        if(rotate) {
            temp.setDefaultPageSize(pageSize.rotate()); /** Page Size and Orientation */
        } else {
            temp.setDefaultPageSize(pageSize); /** Page Size and Orientation */
        }
         HtmlConverter.convertToPdf(htmlPage, temp, properties);
        temp = new PdfDocument(new PdfReader(new ByteArrayInputStream(baos.toByteArray())));
        merger.merge(temp, 1, temp.getNumberOfPages());
        temp.close();
    }
    pdf.close();

    byteArrayOutputStream.flush(); // Tried this

    byteArrayOutputStream.close(); // Tried this

    byte[] byteArray = byteArrayOutputStream.toByteArray();

    Timestamp timestamp = new Timestamp(System.currentTimeMillis());
    try (FileOutputStream fileOuputStream = new FileOutputStream("D:\\Labels\\Label_"+timestamp.getTime()+".pdf")){
        fileOuputStream.write(byteArray);
    }
    return byteArray;
}

Thanks in advance.

Edit 1: You can find pdf and html/css for reproducing issue here.