How to make proper hair collision?

I have a skeletalmesh which includes hair bone.

I setup hair physic in Phat editor. Now I need to make the hair bone collide with skeletalmesh itself.

I enabled the hair’s physic body’s collision response in Phat editor. But when I PIE, the hair goes wild, hair bone randomly bounces around.

If I disable collision response, physics works fine except without collision.

What is causing this issue? and how can I solve it?

thk.