See if "Different first page" or "Different odd and even" is selected on the Page Layout tab. If both of these options are selected, the section has three different footers (and three different footers). "Different first page" can be set for individual sections while "Different odd and even" always apply to all section, if it is selected.

To see all headers and footers in a section, and be able to link/unlink them, you will have to (temporarily) insert manual page breaks, so that the section is at least three pages long.

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Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional