Hair curves randomizing with movement

I’m noticing a problem with the hair
Let’s take the attachment as an example, I apply a blend shape to the mesh on which the hair is to be able to move it in space… To simulate an animation.
By doing so a disaster happens with the hair noise node… At every slightest movement the hair moves, and it’s not good. Why?
can’t I tell it to block them as they are?

I download the file from blender site and only make a blend shape on the head that work from frame 1 to 40. I haven’t touched anything else