Font changed to a different when opening existing PDF

[anddrzejb]

Hi

So I load an existing PDF document using

PdfDocument document = PdfReader.Open(new MemoryStream(pdfStream), PdfDocumentOpenMode.Modify);

The document has these fonts defined:

However when I save the pdf, the font is different:

Am I doing something wrong or this behaviour is expected? How can I ensure PdfSharpCore won't change the fonts (or anything visual for that matter)?

The PDF was generated on the same machine by Playwright - actually, in the same process.