Just a thought, what about the properties of the pdf on Windows?
What PDF reader on the PC are you using? Also what version of filemaker? I know there has been some PDF issues that were ironed out in the latest 12 update - 12.0v4
The properties of the PDFs created on all three platforms (PC, Mac, iPad) are identical. Printing: Allowed, Document Assembly: Not Allowed, Content Copying: Allowed, Content Copying for Accessibility: Allowed, Page Extraction: Allowed, Commenting: Not Allowed, Filling of form fields: Allowed, Signing: Not Allowed, Creation of Template Pages: Not Allowed.
Adobe Reader on the PC and Mac is 9.5.5.
FIleMaker on all platforms is the latest, 12.0v4 for the computers, 18.104.22.168127 for FileMaker Go 12.
After a bit more testing here is what I discovered.
For a PDF created on the Mac or iPad, it is selectable on all platforms, using Adobe Reader.
For a PDF created on the PC, Adobe Reader will NOT allow selection of text on either the PC or Mac. However, using Preview on the Mac and using Foxit on the PC I can select text in the PDF.
So while there is a difference in how FMP creates a PDF on a Windows platform, it is only Adobe that seems to have a problem with it.