PDF layout differences between Windows/Linux

Depending where physically located, I sometimes use the Windows version of Scrivener and sometimes the Linux version, synced via Dropbox. When I compiled to PDF on both systems though, the Linux version was formatted differently; the margins and font sizes came out considerably bigger on the Linux version despite no settings changing. A ten page screenplay on Linux became a nine page screenplay in Windows and the font sizing looked more like what I’d expect for 12 point.