I just noticed that Spotify has ignored the setting "download over cellular" burning through 1,6 GB of data (almost my monthly bundel) in a day.
I'm running:
Spotify 8.4.19.792 armV7

Android 7.0

Samsung Galaxy A5 2017

Samsung Experience 8.1

As this turned up just after my Premium died (cause I switched ISP, I have Premium directly now) it had kicked all downloaded data off my phone (it would have been nice to have some kind of warning for it, but that's another matter), and it started downloading EVERYTHING over cellular until my safety features cut it off. There still are a couple of days left on the month and now I can't use data anymore.