Same issue here.
It seems like after you have triggered the wrath of the King the event script would put the permanent curse on you.
> Start the fight as SWORN Fane
> Reject releasing the death fog
> First punishment from the King
> Broke the Covenant with Fane -> Got Bless instead of Curse, Covenant quest updated
> When I leave the area I got cursed and cannot remove it
Hope it's gonna be fixed before I finish the game.
