I don't use the "download" feature but Spotify is forcing it on me.
When I launch the app, a random album or playlist I recently played will attempt to be downloaded. It only occurs when the app is just launched.
Been using Spotify for several years and this behaviour only started recently (on and off for the past few months).
It seems like a feature to download songs that you've recently liked but it's inconsistent and there doesn't seem to be an option to disable it