There’s a bug with Ravaging Stance (& presumably the other stances as well) whereby you can have it active until you log out despite not having it on your bar.
If you cast Ravaging Stance, then remove it from your skill bar the effect remains active (until you “re-equip” Ravaging Stance then turn it off). You can even remove points in Void Knight such that you can no longer equip Ravaging Stance in the first place!