I don't use FTM, but have noticed problems in other software, so . . . .
Check the printer settings in FTM - are they set to A4, or American Letter size?
A4, as used in the UK, is 8.26 inches by 11.69 inches (210mm by 297mm).
US Letter paper is 8.5 inches by 11 inches (215.9mm by 279.4mm).