Why do I have to download a song to look at any playlist in my library?

before I updated my phone I could find ”My Favorites playlist“ in my library, then sometime after the update I realized I had to have other music in my library to see anything in my library. The annoying thing is when I get in my car it automatically starts playing from what ever is in my library. Since I only have one song in my library just so I can see ”my favorites playlist“ it gets really really annoyin.