There has been a plethora of printing issues, including printing from PDFs.
Because its finals and most students won't have time to troubleshoot, the Adobe DC support page has recommended this as a quick fix:
1. Open the file in Acrobat
2. Go to File > Print
3. At the Print screen after page size and other settings are set go to Advanced seen below highlighted in blue
4. On the next screen toggle on the Print as Image just like below:
Hit ok and proceed to print as usual. This should resolve any issues with transparencies or fonts that maybe causing issues with the printer.