Custom Metahuman use Face_AnimBP Problem(Using Face_AnimBP will cause head deformation)

I use custom heads and bodies to replace the metahuman preset. Due to my custom head being shorter than the original model. When I use Face_AnimBP in the character BP, the head of my custom character will be stretched.

When I delete “copy pose from mesh” in Face AnimBP, the character’s head shape becomes normal. However, when using character animation in the sequence, the character’s head will no longer move with the body.

My preliminary diagnosis is that the default posture of metahuman does not match the proportion of my latest model, which caused a problem when using “copy pose from mesh”. How can I solve this problem