try this think it is the only half decent way to do it

Open player.
In top-of-screen menu select one of the choices - All Songs, All Albums, Artist, Genre, or Playlist.
You now have to start playing a song to get to the Now Playing screen - only then can you save or create a playlist.
In top-of-screen menu select "Save Playlist". That will save or create that one song in a playlist.
To add more songs go back two screens to Songs, Albums, etc.
Press and hold a song to add it to the current playlist. Repeat for more songs.
Go back to the Now Playing screen again, and do the "save playlist" process there again.
It will ask you to enter a playlist name. It will not bring up the lists you've already created, so it looks like you're creating a new one - you're not. Dumb...
Enter the exact spelling of the current playlist and save. It will ask if you want to replace current playlist with this one. Again dumb. It's the same playlist, just being updated. Ignore logic and say yes.
Now you have created or updated a playlist.