PoE 2: Life Thief Bugged?

It says '9% Of Physical Damage is Leeched as life'.
I set it for Explosive Shot, which says it does 183-680 Physical Damage.
I also have the UI set to always show my health numbers.

Hitting enemies with Explosive Shot is not healing me at all.

I also set it to the default 'Crossbow Shot', which does 239-865 Physical Damage.
Still no healing applied on hits.

Having the same problem, doesn't seem to do anything whatsoever w/ physical damage.