How can I adjust Genius Playlist song limits on Mac?

I'm no longer able to change (increase from the default 25) the number of songs in my genius playlists. Any ideas about how to resolve this?

• I see this Apple tip: "Change the maximum number of songs in a Genius Playlist: Click  next to the song total, then choose a number from the pop-up menu."

I no longer see the the number iof songs of the option to click. What am I missing here? Thanks for your advice!

[Re-Titled by Moderator]