[AC Question]

One of my quick setting buttons turned into a light green color like the multiWindow button and whenever I tap it, it stays the same.

[VidJunky]

Which button, what function? Does anything change when you press it? It could be an app that has permission to control whatever that function is and when you disable it the app says no I need that and enables it again. Trying to change the state from the regular setting location shouldn't be any different than the quick setting location, but have you tried changing it there to see if you can change it at all? If you can change it from the regular settings location but not the quick location it could be a bug in your OS.