Lines Scale in Layout: presentation, print , print preview

Hello, I attach some doubts about scale lines: dashed lines and dot dashes etc…
I attach three images to better understand the subject: a pdf, a presentation view and print preview.
Both images have different line scales with the same defined values.
The PDF does not present the lines in the same way that we see in the layout, since with the increase decrease zoom the lines change the scale, even with the option of 100% visualization it is not proportional.

At print preview appears black spots ???

I tried to use the auto option but as dashed lines and dot lines appear continuous…


The Windows Print Preview is notoriously unreliable. What you get will ultimately be seen only by examining the actual printout.
Screen line widths are affected by your zoom factor because they cannot be thinner than 1 pixel. Output is usually much more accurate.