softbody anchor to Kinematic rigidbody failed, the soft cloth fly away

[erickingxu]

Hi,@Phong13,
Thanks for your great work.
I try use your bullet uinty script to simulate a skirt mesh anchor to a Kinematic rigidboy in hip root bone node.
Everything was created and seemed very well. Some details are showed as follows:

But I stepsimulate and redraw this skirt mesh , it fly away around rigidboy node.

So what key points was lost for me?