I've got everything worked out with the page breaks and the headers.

But now that I check carefully, I see that throughout this 340 page file, some of the page numbers in the footer are 1.5 cm from the bottom of the page, and some of the page numbers in the footer are 1.9 cm from the bottom of the page. In the roman numerals at the beginning of the file, it seems to be mixed between even and odd pages. But once the standard numbers begin, it seems to be restricted to the even pages, but not all the even pages are affected. I would like them all to be 1.5 cm from the bottom of the page. How can I standardize this for all the pages?