Select the Hatch inside the section view.
In the Properties pane:
Uncheck Material crosshatch.
Press Green Check.
Thanks but I've done that. It shows up correctly on my screen, but it does not print that way.
This is a known bug that solid hatches don't always print or export to a pdf as such, and has unfortunately been known to solidworks for a few years at least without them doing anything about it. below is the workaround. I used a hatch scale of 20 which was sufficient for printing as solid, much more is probably overkill and in fact when I tried a scale of 500 it took a long time for the PDF to load after scrolling or zooming.
Summary:On broken views, solid hatches fail to save as a PDF.
Comments:Workaround is to use a non solid hatch with a high value for
hatch pattern scale. This will appear solid in PDF.
DS SolidWorks does not guarantee that this SPR fix will be available
in the indicated future release of the product since at this time the SPR
fix has not completed QA procedures that incorporate all SPR fixes and
enhancements into a new version of our product.