Widow/orphan control doesn't work

I've read in this forum and elsewhere about how to force Pages to avoid widows and orphans. I can't get it to work without going a step further. I check the box to "Prevent widow and orphan lines," but a simple one-sentence paragraph stubbornly appears with three words at the top of the page that follows. I then check the box for "Keep lines on same page," and I get what I want.

I've rarely had trouble with controlling widows and orphans in Word. I know Pages lacks the features of Word, but I feel like I'm overlooking something. Any thoughts?