Playlist Radio autoplays after connecting to wifi

[Kaelpe]

I will pause my playlist, close out of Spotify, and when my phone connects to any wifi network the app starts autoplaying a playlist radio based on the last playlist I listened to. I have streaming set to wifi only.
It wastes my battery if I leave my headphones plugged in and don't notice it's still playing, and is disruptive if I don't leave my headphones in because suddenly random song I didn't choose starts to play in the middle of work or class.
I have a Samsung Galaxy S6 with android.