Description:
Text in the document header/footer areas align right, left and in some cases center. When we change the page orientation from portrait to landscape, the tab settings leave the text short of the right margin, and in the case of a centered page number, off center.
Cause:
These text positions are set using tab settings in the paragraph styles for Header and Footer.
Resolution:
Word has a feature to automatically align text to the header/footer margins. The tabs can be removed from the text styles and the header/footer alignment tabs used instead. The attached video demo shows the location of this feature in Word.