None other options were checked. However, I do notice that there is a footnote associated with the first line of the following page in instances where there may be room for that line but not for the footnote on the preceding page (the footnotes are long).

Word will keep a footnote on the same page as the text wherever possible. If there is not room for it on the page where the text would appear without the footnote, it will drag it to the next page. In doing so, it will, I believe, follow any rules set for widow and orphan, keep lines together, and keep with next formatting. So, it can cascade.

I personally prefer footnotes, but might it improve your document if you used endnotes instead?