So i'll try and explain this as good as I can since the problem is quite weird.
I have Spotify open on a second monitor, when the Spotify window is selected (changing songs, switching playlists or just having it marked) the sound is the way it should. As soon as I mark another window (no matter what window) the sound quality drops. Not only the quality but aswell the sound. If I then go back to marking the Spotify windows the quality and volume bumps up.
This has never been a problem before and the troubleshooting i've done is:
Restarted computer and Spotify
Mixing with sound settings in windows (no sort-of "Allow other devices to take full control")
Googling for other issues and tried that solution. I've also looked through the spotify settings and I can't find any solution.
The PC is a Lenovo T570 in a Lenovo Ultradock running Windows 10 64-bit.
Let me know if you need anymore info! 🙂