Desktop Windows(tested on 10 and 7)
Desktop Version : 18.104.22.1680
1 - Preferences > Playback settings : Turn Crossfade and set the same volume ON
2 - Close the desktop app
3 - Open the desktop app
4 - Playback settings are OFF
Update : According to @MattSuda comment, it seems the issue is the same on Mac.
Sorry to hear! Thanks for letting us know you're also experiencing this.
This is being looked into already, at:https://community.spotify.com/t5/Ongoing-Issues/Spotify-Doesn-t-Save-Advanced-Settings/idi-p/3769361If you could add your comments to the main thread, we'll be able to better help everyone in the same place 🙂
This happens to me too on Mac. So it's not just Windows. Instead, most likely a problem in the app.
I can also reproduce this on my MacBook Air (Spotify Version 22.214.171.1248.g8e1ed5af, macOS High Sierra 10.13.2, Early 2014 MacBook Air).
Mine doesn't even stay selected through one listening session. I was listening to a playlist yesterday and it was deselected halfway through. Spotify, fix this!
This is occuring for me as well on Windows 10. An interesting thing I've noticed is that this may only be a matter of the toggles not displaying correctly while the settings themselves are staying intact, i.e., I'm noticing that crossfades are still being applied between tracks even though my settings say it's turned off.