The “jump to page” is not global. If you are, for example, in section 40, page 8, which is page 120 of the whole document, and ask to jump to page 3 right in the very beginning because you want to edit the table of content, it will jump to page 3 of section 40, which is page 115. There is, as far as I know, no way to jump to global page counts instead of the section ones.

Oh, but to make the chaos perfect, if your section has 20 pages, but you tell Word to jump to page 40, THEN it WILL use global page counts. Weirdly counterintuitive.