Hi there! I understand you’re looking to recover your lost downloads and favorites in the Napster app on your Mac running OS X 10.15.7. Let’s start by narrowing down a bit:

- When did you notice your downloads and favorites were missing?
- Have you recently logged out, reinstalled the app, or changed any account details?
- Are you still logged into your original Napster account in the app?

Knowing this will help me guide you better. Meanwhile, I’ll give you some initial steps we can try to recover your missing content.

### Step 1: Verify your login credentials
- Ensure you are logged in with the original account where you saved your downloads and favorites. If you’re unsure about your password, you can reset it through the app or website.

### Step 2: Check “My Music” section in Napster
- Open the Napster app, then go to “My Music.” This is where playlists, favorites, and downloaded tracks should be stored. Sometimes content seems missing due to app glitches but is still listed here.

### Step 3: Refresh or sync your library
- Sometimes the app needs to sync with the Napster servers to retrieve your library. Try signing out and then signing back in. This action can prompt the app to reload your playlists and favorites.

### Step 4: Check Downloaded files location on Mac
- Your downloaded tracks are stored in a protected folder managed by Napster for offline listening. If you uninstalled the app without first removing downloads through the app, the files might no longer be accessible.

### Step 5: Update the Napster app
- Make sure your Napster app is up to date. Sometimes bugs affecting saved content are fixed in updates.

If you’ve tried these steps already or the issue persists, let me know which ones you’ve done, and we can try some advanced troubleshooting or check if there is a known server issue causing this loss.

Are you currently able to access the Napster app and see your account details? That will help me guide you further.