Just to confirm, do you still experience this after running a clean reinstall of the Spotify app on your iOS device? This will remove corrupted data from previous installations that could be causing the issue.
In case this persists, make sure no battery optimization settings or data cleaning apps run active on your mobile device. Such features can often prevent the app from operating at full capacity. We also suggest accessing the app settings and making sure all Permissions are enabled for Spotify.
Let us know how you get on! We'll be here in case you need any further help with this.