After I added a footnote, I noticed that there was an extra blank line right before the text that originally started the second page before the footnote had been inserted. I can't figure out how to get rid of the space. I've attached screenshots with the area highlighted.
I'd check the leading for the line after the gap. Maybe it is a coincidence, but the 12 lines above the gap on p. 2 look like they would fit on p. 1 without the the footnote, as if before the note was added someone increased the leading for the line after the gap to equalize the positions of the first lines on pp. 2 and 3.
Where does the baseline grid start?