The main issues users have when they connect to Spotify are：
1. Massive queues in communicating with your account
2. A continual buffer of music
3. Stutter in Tracks
4.You see, there really is a connection problem, or try again later

Fix Spotify Not Working
1. Close then reopen Spotify
The Spotify application may have a small technical problem. Closing or reopening the application will correct a small technical error.
2. Check the Spotify server
Sometimes Spotify's databases collapse, leaving it inoperable to all. This takes a touch of patience since you can't repair the networks. Confirm the progress of Spotify databases.
3. Refresh the iPhone
It's very quick to restore your iPhone. Much as shutting and reopening Spotify solve basic problems, so you can reboot your iPhone.
4. Verify the Wi-Fi or Mobile communications if ok.
Be sure that the button beside Wi-Fi is on and a blue checkmark shows beside the label of the Wi-Fi network. Try flipping off again and back on that if Wi-Fi seems to not work.
5. Review for an update to Spotify
Open the Application Store and touch the symbol of your profile within the upper hand corner of the window. Scroll down to the updates menu that appears and see whether an update is released for Spotify.
6. Uninstall then reinstall your Spotify App
Maybe there was a technical problem which can't be fixed only by resetting the device or iPhone. If this occurs, the simplest option is to uninstall and reinstall the program.

Play Spotify Offline without Error
It would be to use trustworthy third-party software to import Spotify songs, collections, and podcasts to portable copy.mp3. The TunesFun Spotify music converter is an application that you can use to download Spotify music even without an internet connection.

Thank you. AMusicSoft Spotify Music Converter is also a good choice to fix this. AMusicSoft Spotify Music Converter helps you easily remove the DRM protection from Spotify songs and playlists. Now you can download Spotify music on any device for offline listening and enjoy songs anywhere.
https://www.amusicsoft.com/spotify-music-converter/