How do I sort a smart playlist in iTunes?

I have some smart playlists in iTunes. Some of them display with headings that I can click on to sort by Name or Artist or whatever I have displayed. But other smart playlists do not have this heading, and are sorted in some unknown way. They often have a colored background. I haven't figured out what's the difference between these smart playlist and my older ones. But without the heading, I can't sort them and find the song I'm looking for.

iTunes 12.4.1.6