Hello jcutolo,
You've come to a great place for help! With the playlists showing doubled, quit and reopen the Music app. While simple, it is a step that can help resolve many app specific issues. You can find the steps for quitting an app listed below. You can also find these steps outlined in the following article.
- "Take either of these actions:
- Press these three keys together: Option, Command, Esc (Escape).*
- Or choose Force Quit from the Apple menu in the corner of your screen.
2.A Force Quit window opens. Select the app that you want to quit, then click Force Quit."
How to force an app to quit on your Mac
As for macOS showing incorrectly. Let's restart the Mac by clicking the Apple logo towards the top-left, followed by Restart in the menu. This can be a lucrative step to resolving this issue as well.
Have a great day!