Convert into an other PDF-Format

We found out, there are some PDF-Files which we try to convert to PDF_UA_1 and as Result the font is corrupted. With other Files there are not converted, but also not corrupted. What is the Problem with this files und why some text seems to be ok, while other paragraphs fail.

Document pdfDocument = new Document(“input.pdf”);
pdfDocument.validate(logbaos, PdfFormat.PDF_UA_1);
pdfDocument.convert(System.out, PdfFormat.PDF_UA_1, ConvertErrorAction.Delete);
pdfDocument.save("result.pdf, SaveFormat.PDF);

input.pdf (140.7 KB)
result.pdf (255.6 KB)

Can you give a hint?

@b.schalitz

PDFwithTagged.pdf (137.8 KB)

Attached document is generated using 23.12 version in our environment. Can you please check it and share the screenshot if your notice any font related issue?