Kor Dragan bugged?

I cannot seem to liberate the Kor Dragan stronghold seeing as how there's a vampiric tumor that never becomes vulnerable.

I found a note talking about how "the infection starts underneath the cathedral," and there is a side dungeon you can do on the outskirts of Kor Dragan that has vampiric tumors, but it doesn't unlock anything for progression in the stronghold AFAIK.

It kinda sucks because there's a waypoint that's locked away in the stronghold that can't be accessed until it's liberated.