In LibreOffice Writer, I set a board at the top of the footer and it shows up on the page. If I save the file and re-open it the border is gone. If I go into the border settings it shows that no border is set. What may I be doing wrong?
I just discovered that if I save the file as an ODT the border remains. If I save it as DOCX it will not be there the next time I open the file.
There is no “border” property in Word for headers / footers. It simply lacks that feature, and its file format has no option to store it.
Your only option is to use paragraph’s border, if you need interoperability with DOCX.
As an alternative for docx you can create a drawing line (hold down Shift to keep it horizontal) and anchor it to a paragraph in the footer so it appears on all pages.
I have seen this in documents originating in Word