I have a 100-page document with 5 sections and Word doesn't save my page numbering format in some sections.

In every section I clicked on the Footer, then on Page Number>Format Page Number>Page Numbering> Continue from previous sections.
Clicked OK.
I verified the document and all the pages are properly numbered according to the setup. Then, save and close the Word file.
When I re-opened the Word file, some sections don't have "Continue from Previous Sections" configured despite I saved the document. Of course, now the page numbering is completely distorted.