I have had this problem for quite a few days now. I have a Huawei y520 and I have the Spotify app on it. The thing is that, every certain time, I keep getting asked to log back in, which is only able to be done while connected to WiFi. The most annoying and irritating part of this, is that it desyncs each and every one of my playlists, and I have to manually sync them ONE AT A TIME. Is there something I'm doing wrong? I've tried uninstalling and reinstalling, getting password for device, using offline mode, but as soon as I exit the app for a while, it just keeps asking me to log back in, and it keeps desynching my playlists. It becomes really frustrating since I have a lot, and it is really stupid to have to manually sync them one by one.