PC: Soft lock, died at the same time as the Act 4 boss in The Excavation, door won't open

I killed Benedictus in Act 4 at the same time I died, and I saw the cutscene where he takes off on the rock and gets monstered by the guy with the axe. I saw the loot drop as well. I hit respawn to checkpoint, and now no matter what I do, when I respawn by the arena I see and hear his speech, see him come up on the rock, and then just vanish. The door will not open. I've tried relogging, changing areas, reopening the game, everything I can think of. I'm softlocked and cannot proceed any further.