nisus.com

If I write some text and then execute the menu command Insert –> Section Break –> Same Page, a new section begins at the insertion point on the current page and the text of the new section will appear on the same page as expected. However, as soon as I add a footnote in a section, a blank space will appear on the same page below the section break. Is this a bug or intended behavior?

This is not a bug; it is a limitation of NWP. Any main text of a following section appears only after the footnotes of the previous section.
https://nisus.com/forum/viewtopic.php?f ... ete#p29856

Thank you Hamid.
Using the search term "limitation" I just found an almost identical thread from 2015. Then Martin's answer was:

I'm glad you ferreted out the culprit Timotheus, but unfortunately there is no way to prevent the unwanted behavior. This interaction is an unfortunate limitation in our page view's pagination. I'm sorry for the confusion and limitation.

http://nisus.com/forum/viewtopic.php?f= ... ion#p28237

PS
It's interesting to notice that Mellel has the same limitation! Not that it creates a large empty unwanted space, but rather it puts the footnote after the section's text instead of placing it at the bottom of the page.

Another limitation, as far as footnotes are concerned, is the impossibility to insert footnotes into table cells. This is possible, however, in Mellel, and if I remember well also in Word.

Nisus and Mellel are two most excellent applications, but the handling of footnotes is improvable in both.