Elevation shadows print very dark when printing directly from Archicad

[ETSaum]

When printing directly from Archicad, the shadows on my exterior elevations are almost black. When printing a saved PDF from either Acrobat or Bluebeam, the shadows are much lighter, but tend to pixelate.

What might be causing Archicad's 'print' feature to essentially print shadows *black*, when any PDF Archicad generates shows them properly grayscaled?

It happens on both the small scale 12x18 printer and the plotter.

Operating system used: Windows 27 5003