Hi @Anonymous 

Yes, there is such defect (bug) in AutoCAD 2016 for Mac.

Please try this workaround:

https://macacad.wordpress.com/2013/04/03/workaround-for-printing-solid-hatches-with-transparency-in-autocad-for-mac/

BTW, since 2019 version AutoCAD for Mac uses the same PDF engine as AutoCAD for Windows and there is no such issue in AutoCAD 2019, 2020 and 2021.