When navigation links are repeated on multiple pages, the order in which they appear on each page should be consistent.
On this page:
This makes it easier for people to learn how to navigate the website/app, and it enables people to develop strategies (like using screen reader shortcuts)for more efficient navigation.
3.2.3 Consistent Navigation: Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user. (Level AA)
See the W3C’s detailed explanation of this guideline with techniques and examples.