Sacrifical heart - act 6 (cruel 3)

I had both hearts from act 3 and from act 6 and managed to redeem the first (in act 3) but the other has vanished from my inventory. I only managed to get one set of the points (from act 3).

I cannot find the drop afer clearing the act 6 utzaal map and the blood sacrifice marker still exists.

Hoping this can be resolved.