What has been observed in the PDF export is expected functionality. All Multi-Page Views within a Dashboard exported to PDF will show the same behavior.
That Documentation has the following statements related to this scenario.
When creating PDF of a Dashboard "on-demand" it states:
"Export a dashboard to a static report in PDF format. The PDF includes only the information currently visible in your dashboard."When emailing/scheduling a PDF run it states:
"For First Page, only the first page is attached and sent in an email message. For All Pages, an email message is sent with a time-sensitive link to the report containing all pages"