[GAMEPLAY] Sion Passive Damage Bug????

Sion can freely move and use basic attacks during this time, gaining Life steal icon 100% life steal, attacking at Attack speed icon 1.75 attack speed, and dealing 10% of the target’s maximum health bonus physical damage on-hit, capped at 75 against minions and monsters.

Sion's passive used to give him bonus damage to the inhibitors and nexus. It was like this a patch or two ago but I haven't played till now. It no longer does bonus damage to the inhibs and nexus when he dies and I'm wondering if this is a bug? I realize it could have been a bug before and now be fixed but I didn't see it on the patch notes so I'm not too sure. I just want some clarity.