Hi, I'm running the Spotify app on Android Pie, but this also happened on Oreo and Nougat.
I like to download my playlists and then turn on offline mode to avoid using data plan. But after a time letting app closed, not like days, but just hours, when I re-open it, it logged out automatically and won't let me log in again, as offline mode is still enabled, so I have to clear app data to use it again.
That's happening with my father's account, which is Premium, but seems like an app bug. Is there any way to avoid it?