glider1
Deity
If a Master + Vassal declares war on you, and you completely eliminate the Master, does the Vassal automatically get peace with you? No. Therefore, there's no reason the Vassal should automatically get peace if the Master is "eliminated" by capitulating.
Bh
I see where you are coming from in terms of seeing the vassal behaviour as an overt "bug" Bhruic.
Could I just cement the main criteria for Bhruic continuing his excellent efforts on bug fixing BTS 3.13? That is Sid Meier's original adage "whatever you do to the game has to make it more fun." By fun we mean simple unadulterated "fun". Not academic correctness.
The adage applies to the fixing of "bugs" as well. So when I look through Bhruic's bug fixes INCLUDING the vassalage "bug", all of the changes pass the Sid Meier test.
However if Bhruic would have implemented the State Property "bug", that would not have passed the Sid Meier test because it only produces a neutral outcome at best (neither one way or the other).
So Bhruic, you're judgement as well as your talent have been first rate to this point. Cheers, enjoy and thanks.