There could be several issues involved, @tom.au. The direct PDF generation feature was only added a couple weeks ago and there were many issues across all platforms. Fixes and improvements have been happening several times per day. So first, make sure you have today’s version of the software installed. Some of what you show has already been fixed.
It is also important to make sure you have exactly the same version on both your computers. One may still have the bug while the other has a version where it was fixed.
It is also common when PDFs are generated that some features do not render correctly in previews at some scales. Try blowing up the view. I experienced exactly the same cutoff problem you show at the left. But when the view was expanded, it resolved.
You can also expect some variation in spacing between screen and PDF views.