AttachActorToComponent moving problem

Hi. I am trying to attach Actor to child component of BP actor in construction script. When I move the whole BP actor everything works fine. If I move the child component, attached actor moves the double amount of relative location of the child component. Here is video if I couldn’t explain it: - YouTube
Is there any way make this work? Thanks.

I am punching myself here out of rage D: My months of work is stuck because of this… HEEEELP!!