Flex Pitch hotspots not always available

I am using Flex Pitch on three vocal tracks, but even though I've got the exact same settings for each of these tracks (Flex select at the top of Logic Pro, Flex Pitch selected for each track, the Flex box checked for each track), I only get Flex Pitch hotspots on two of the tracks. The other one has no hotspots. I can see "Fine Pitch," "Vibrato," and the other labels if I hover over those areas, but when I drag them, they don't change the values. Yes, I can hear the pitch change while I'm dragging, but then when I play the audio, it has not changed at all. And when I drag the "Vibrato" label, the vibrato does not straighten out as expected.

This would appear to be a bug.

If not, I hope someone can tell me what I'm doing wrong.

Thanks.