Bugged Tooltip on Wooglet's Witchcap (Gameplay)

During Hexakill Twisted Treeline last week, I noticed that the tooltip for was not displaying correctly. While playing as I noticed that the ap scaling of the unique passive (green number) was zero reguardless of how much ap I built. When I played again as the bug occured again. I am unsure if it is just the tooltip that is displaying incorrectly or if the unique passive of has stopped working altogether.