Bloody Bargins - Min Cho's Father can not be damaged

Version: [email protected]_ConanLiveWin32_2018 Revision: 587987

I have the quest Bloody Bargins (Brittle Blade quest in Shaulun), and Min Cho’s father: You-cheng, at 929.6 720.9 y 339.6 6300, is on my quest list to kill however I deal him no damage when I attack him. He has a yellow name tag to my character, but takes no damage.
I am on my demonologist and I can set my pets to attack him and he takes no damage. I can not cast a spell on him directly (ie Shock, Hellfire stream will not activate). When I cast Waves of Flame over him he takes no damage and does not react.
I have killed the three other NPCs on this quest line tonight and upon attacking them, they reacted, attacked me in return and their names turned to red.

This quest did complete after the Saga merge into Crom. I had not tried it since the last hotfix however.