Hi Amit,
What specific version of oXygen v19 are you using (v19.0/v19.1)?
What transformation scenario are you running? Is it the DITA Map PDF, or the DITA Map PDF WYSIWYG?
Also, on what machine (which operating system)?
I have just tested the behavior in oXygen XML Editor v19.1 (available for download in the software archive) by publishing a DITA Map that contains a topic with <menucascade> element and the separators appear just fine in both the PDF and PDF WYSIWYG generated outputs.
However, there seems to be a fonts related issue at your side.
In case you are using the DITA Map PDF WYSIWYG scenario, are you using a custom CSS to style the output? I am asking this because you could have set a specific font through the custom CSS, that is not correctly rendered in the resulted PDF.
If you do use a custom CSS, you should first try applying the predefined DITA Map PDF WYSIWYG scenario, without any customization and see if this solves the issue.
If this still does not work, you should try setting a different font, using a custom CSS. More details available
in the User-Guide.
The same for the DITA Map PDF scenario. As long as you did not tinker with the XSL stylesheets from the PDF plugin of the DITA framework, the out-of-the-box DITA PDF (or DITA Map PDF) transformation scenarios should correctly render the separators in the output. If you using the predefined DITA Map PDF scenario (not a customized one) but are not sure anymore if you modified any default XSL files, you should try deploying a clean installation of oXygen XML v19.1 in a separate folder and try running the DITA Map PDF transformation scenario from the clean oXygen.
Regards,
Costin