FD uses the Print settings on your device to create PDF files, so it's likely that the Print settings have been set to print in reverse order.
In Final Draft, click File > Print. That'll open the Print settings window, and towards the middle of the window you should see Back to Front next to a box that's likely checked. This is how it will look on Mac:
and on Windows:
If the box is checked, uncheck it. Now you should be able to create a PDF that populates front to back.