I'm a mathematician running Mac OS X 10.14.6 and when I print PDF documents such as https://eprint.iacr.org/2020/1240.pdf certain letters, like the I in SQI in the abstract, do not show up in the printout. I've updated the firmware to no avail. I wonder if this is some sort of font issue, but it's quite odd to have BMP characters go away entirely.
Seems it is pretty common having problem printing PDF.
And usually it is said it can depend on
- the PDF file it self, print from cloud or local.
- The PDF application and fonts.
- Driver printer.
A quick fix is to print as image.
Adobe Acrobat - Quick fix print pdf image