Exporting diagrams to PDF

Polish national characters disappear when exporting diagram to PDF. Should I define some font substitutions or it is an error?
Attachments below show the particular diagram (jpeg file) and it’s pdf export.

AO Anulowanie transakcji.pdf

Anulowanie transakcji.JPG

Hello Jacenty,

I will discuss with our engineers and then get back to you.

Best regards,

Hi Jacek,

Sorry but to say that we are unable to support Polish at the moment. This is due to the engine we used to generate the PDF content does not support Polish. Would you consider generating PDF report instead?

Best regards,