There could be several reasons why your Spotify playlist is getting interrupted. Here are some possible causes and their solutions:

1. Poor Internet Connection: Spotify requires a stable internet connection to stream music. If your internet connection is weak or unstable, it might cause interruptions.

Fix: Check your internet connection and try switching between mobile data and Wi-Fi to see if there's a difference. You can also try restarting your router.

2. Outdated App: If your Spotify app is not up-to-date, it might cause some issues.

Fix: Check the app store or Google Play Store for any available updates for Spotify.

3. Cache and Data Issues: Sometimes, the Spotify app might have stored too much data, causing it to lag or interrupt.

Fix: Clear the cache or data of your Spotify app. You can do this in the app settings on your phone.

4. Too Many Devices: Spotify might stop playing if it's being used on more than one device.

Fix: Make sure to pause Spotify on one device before you start listening on another.

5. Spotify Server Issues: Sometimes, the problem might not be on your end. Spotify servers might be down or experiencing issues.

Fix: Check online to see if other people are having the same issue. If they are, you'll have to wait for Spotify to fix the problem.

6. Device Limit: Spotify Premium allows you to download songs on up to 5 different devices. If you've reached this limit, you won't be able to play downloaded songs on a new device.

Fix: You can remove a device from your download list by going to the Spotify settings.

Remember, if none of these solutions work, you can always try uninstalling and reinstalling the Spotify app. Sometimes, a fresh install can help resolve any issues you're experiencing.