OK, next question:
You're telling me ALL pens, that is everything Archicad prints, get the same pen weight. Are they also the same colour? If that's the case, what colour?
and, if you print directly from a model window (a plan window for instance, not a layout) do you get the same result?
and, do you have ANY (Options>Element Attributes>) Pen set in your project that contains the pens you get when printing?
do you use ANY of the print options (print dialog) hairline/black&white/greyscale?
what happens if you do?
did you check, with a layout selected in the Navigator, the Options>Layout Attributes>PenSets menu command?
did you, with any placed view on a layout selected, check the actual used pen set in the DrawingSelectionSettings dialog?
and did you notice you have the same print options as in the Print dialog in the DrawingSelectionSettings dialog too, that is B&W, Greyscale etc.?
how did you solve this issue last time (with AC11)?
did you try to print to any other printer?
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1