iOS 17 favorite playlists do not show up in CarPlay unless..

Not really a question since I figured it out. But I don't understand why I can mark a playlist on my iPhone as a favorite (new iOS 17 feature), but then that playlist won't show up under "favorite playlists" in Carplay? I checked all the settings. My favorite playlists even had stars marked on them in CarPlay.

Finally, I added a single song from that "favorite playlist" as a "favorite song." Suddenly, CarPlay now shows that favorite playlist. If I reverse this step, the favorite playlist disappears from CarPlay.

So now I have to mark a single song from each favorite playlist in order to get it to show up in CarPlay's "Favorite Playlist" I sure hope this is an oversight. It's not intuitive and it is not the way this feature works on an iPhone or iPad. And it forces me to add songs to my "favorite songs" that I may not want in there.