[GNC] Font problem

[Paul de Vries]

on Mac OSX 10.11 El Capitan and 10.13 High Sierra, after switching from 2.6.19 to 3.5 a long time ago, I have a font problem. 

I installed GTK3 from MacPorts, then
cat ~/Library/Application\ Support/Gnucash/config/gtk-3.0/gtk.css
* {
  font: 12pt DejaVuSans, sans-serif;
}

Select an invoice, hit the 'print invoice' button.

It is difficult to describe in text, I would like to show a picture, but I suppose I cannot attach it to this mail.

It is about missing parts of letters, lowercase only, for example the down lines (stem?) of 'n' and 'm' or up lines of 'u' have different sizes. It looks like bullet holes in some letters.