19/20 BlackSmoke mountain quests

Hello there,

I know for sure that the only quest missing is the two-cap-vanities ring from the Fallen Prince.
Since I have already got the the three-cap variant ring form the Fallen Prince, I thought to liquidate it, and get both ring.
Unfortunately whatever amount of Cap vanities I wear, the Fallen Prince always offers me the three-cap Ring and then it says he has nothing more to give (I have trired to wear 1 Cap vanity, 2, 3 and even none)

Therefore I cannot complete the quest count in the BSM campaign.

Bug delivered.