I made the font large to illustrate that when the Endnotes extend over one page, the first moves location from directly below the Heading, to its own page. If you change the spacing of the endnote text you can see the endnotes are in the correct location while single-spaced, but the incorrect location while double-spaced. This problem behavior happens when the endnote text range extends past one page.

I've fixed the endnote separator in the attached document. I don't think that was having an impact on my inability to get the endnotes on the same page as the heading, as the problem remains.

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