1. The original songs and playlists may be deleted by their artist or creator. This mostly happens to the songs or playlists that are grayed out after you've downloaded them to your device. It's probably because that the artist or the creator of these songs or playlists does not want these tracks on Spotify for some reason.
See also: Fix Spotify songs greyed out
2. Something got wrong with your Internet connection when you check or download these downloaded songs in Spotify. While you are saving any track or playlist offline on Spotify, an Internet connection is required. So you should confirm the network runs well when you are downloading the songs or playlists from Spotify. If it is this reason that causes your problem, you should download the songs again with a good internet connection.
3. Your downloads of songs from Spotify exceed the 10,000 number limit. As Spotify only allows Premium users to download up to 10,000 tracks in total, you should check whether you have hit that limit or not. If so, Spotify will delete the previously downloaded songs automatically if it finds you adding some new tracks. Normally, you'll be noticed by Spotify with a warning message once you reached this limit.
4. You may be out of Spotify Premium. So you need to verify your premium membership. You are required to log into your account online every 30 days even if you use Spotify Offline mode. Otherwise, the downloaded songs would disappear from your Spotify account.
In other cases, the previously downloaded songs could become unavailable on Spotify if you changed the region of your VPN network. That's because some Spotify songs are not allowed in certain countries and regions. To get the music back again, you should change your VPN network settings.
Unfortunately, we can't cover all the reasons and solutions to stop the disappearance of Spotify songs. But the better news is that we can fix the 'Spotify songs disappeared' issue permanently now.
First of all, you should figure out where the songs go when they are downloaded from Spotify so that you can solve this problem. In fact, any subscribers don't "own" the music even if they have saved it offline. When you are doing this, you only "rent" those songs from Spotify for the time you subscribe to Spotify as you can only play them within the Spotify app. You can't then take the offline files and play them elsewhere. In other words, these downloaded Spotify songs are not downloaded. They are just cache and may keep disappearing occasionally, making you frustrated every now and then.
To prevent the Spotify offline songs from disappearing, all you'll need is a special Spotify music downloader called TunesKit Spotify Music Converter. It's a well-designed Spotify downloader that can download and save Spotify tracks, playlists, and albums as MP3, AAC, WAV, FLAC, etc. for both premium and free plan users. It's able to remove Spotify ads while preserving the ID3 tags and 320kbps bit rate of the tracks.
With the assistance of this tool, you are able to get full ownership of the downloaded Spotify songs and keep them as long as you like in the Spotify library or other devices or players, without worrying about they could expire or disappear one day. Now let's get started to fix Spotify songs disappeared with the help of TunesKit Spotify Music Converter Mac or Windows.
Step 1. Launch TunesKit Spotify Converter and it loads the Spotify app for you. Then find any song or playlist you want to download from Spotify. Drag the file to TunesKit main window.
Step 2. Go to top menu of this Spotify to MP3 Converter and choose the "Preferences" button. Then click the "Convert" section and select output format and other settings, including channel, bit rate, and sample rate.
Step 3. When everything is done, click the "Convert" button to start downloading Spotify songs offline as MP3 or other formats. After that, you can find the downloaded songs from the Converted button. Till now, you are able to save Spotify songs on any device forever.
For more info: https://www.tuneskit.com/spotify-music-tips/fix-spotify-songs-disappeared-issue.html