Leader Pose SKM Attached physic Simulated Bug

Hello, here is the context

I have my blueprint character that use leader pose and is setup as intended and work fine
the leader pose is setup that way, i have an entire skeleton for all part head include

then i have an external SKM as hair with a different rig attached to the principal mesh of the leader pose and a socket.

My problem is that when i activate physic simulation on my character with a Phat setup correctly that dont even have body on the neck or head it work fine BUT it make the other SKM attached to his socket to react like there is something that push the body of the simulated hair and like EVERYTHING is set to ignore in the collision there is not even body to collide which u can see wile looking at the collision ingame i even made a custom channel for the hair to be sure it was always ignore

and it clearly doesn’t look like its a colliding issue when u look at the facts but the visual of the bug realy look like it the other thing i was thinking of is like a force that push the body of the hair because of the animation and the setup or idk,

the way i test it is simply by walking or running with the character and toggling enable physic collision on the mesh leader pose and there is a clear gap its like all the none kinematic body on the hair just teleport and a force push them to their max when it doesn’t occur when the mesh leader pose dont have collision enable

also the hair simulated work fine t’ill i attach it to the leaderpose mesh and then the colliding bug occurs

here a video to illustrate it

i tried discord chat gpt everything no one give me something to work toward