Sacrificial Heart creating 4 dead cells in inventory

In PoE2 at some point towards the end of Act 3, I picked up a quest item called "Sacrificial Heart". At this point in the game, The entryway that turns into this segment of the game eventually gets changed into a portal to enter Cruel Mode.

Since doing that, the portal is now a dedicated "Begin Act 1 Cruel Mode" gateway and no longer takes me to the area where I can use the Sacrificial Heart quest item. The area is also not accessible via the Waypoint map screen. I tried throwing the item on the ground and stashing it away in my stash, but neither is allowed probably on account of it being a quest item.

As it stands, I am working through Act 1 on Cruel Mode but I permanently have 4 inventory cells unusable due to a stubborn quest item. Please help!