Graves cleaver interaction

Since the 7.14 patch, graves and his auto attacks have changed their interaction with the black cleaver. His auto attacks no longer apply multiple stacks at once when attacking next to the target champion. Due to the fact that this was undocumented in the patch notes and still persists in patch 7.15, I am assuming this is a bug. Other abilities such as Ashe Q still apply multiple cleaver stacks at once, but graves auto attacks do not. This is 100% reproducible in any custom game.