Have a look at this video which shows you how you can edit the spacing around the footnote separator. https://www.youtube.com/watch?v=K0SZW_hSrvw

If that doesn't solve your problem, look at the page setup margins for each section and the content in the footer to see where the drivers of that space are coming from. Is there a white floating shape in the vicinity of the footer that is pushing text away from the area?

Next, look at the pagination settings of the text in the vicinity of the bottom of the page. Is there Keep with Next, Keep Lines Together or Page Break Before settings at play?

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Andrew Lockton
Chrysalis Design, Melbourne Australia