In cases when the page numbering is restarted following a section break, Word will add an additional page (a "filler" page) if required to enforce the typographical convention that odd-numbered pages are right-hand pages, while even-numbered pages are left-hand pages.

Since you have deleted a section break, look for any other section breaks that you have not noticed, as Guessed suggested. Usually, it is easier to perform this task in Draft view.

If there are no section breaks, display nonprinting marks and see if there is any hidden content on the "excessive" page.

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Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional