I think you are using Adobe Reader for printing and your Boss are using Preview app (or PDF viewer based on macOS PDF engine). And you are both on macOS Mojave.

Or, if you also are using Preview app for printing, then you are on High Sierra or earlier macOS.

There is a bug in Preview app which resulted in black areas on hard copy, when you print PDF files created in AutoCAD with solid hatches with transparency.

When AutoCAD creates PDF with its build-in PDF "printers" from drawing with such solid fills, it creates raster image with transparency areas (see attached PNG file with such raster image extracted from PDF you attached). Such areas are invisible in PDF, but they exist and Preview app prints them as black areas.

Workaround is to print using Adobe Reader or other application which doesn't use macOS PDF engine. Or convert PDF to raster image before printing.