We Bleed Fire burning duration

In the patch notes I noticed that We Bleed Fire had the burning duration reduced to 3 seconds. Today in Fractals I noticed I had the 4 stacks of burning on me from a fireball for the original 10 seconds it used to be. I can confirm this by going to the fractal lobby and applying the instability to a champion golem and letting a fireball hit me. This appears to be the case for champs/bosses only, as the burning only lasts 3 seconds for normal mobs. Maybe this is intended, but the patch notes would say otherwise.