Hi Scott,
Export to PDF is limited in functionality and restricted to, for example, Portrait layout on A4/Letter page size.
The best solution is to Print to PDF; this supports any page size, orientation and other advanced settings and options.
If you are running Windows 10, this includes a printer called “Microsoft Print to PDF”.
Alternatively you can use third party PDFWriters. There are many available, and one good example can be downloaded for free at
www.cutepdf.com. Again, this behaves like a printer so you just Print to PDF and can use CutePDF's settings to select page size, orientation and quality settings.
PDFWriters have the added advantage that, as 'printers', they can be used to create multi-page PDFs with a page for each drawing, where Export to PDF only operates on the current drawing, creating a single page PDF for the current drawing only..
I hope this is helpful.
Kind regards,
Rob Robinson
Stardraw.com