I can't attach static Mesh to Skeletal Mesh

I’m trying attach my static mesh to a skeletal mesh but it doesnt work very well recently (it was working without any problem).
Sometimes it doesnt overlap with skeletal mesh and sometimes it deosnt attach correctly. I have this problem with only this skeletal mesh and I think problem isnt about skeletal mesh’s Physic Asset.
Video:bozuk2 - YouTube

Edit: I made my static mesh projectile but it still doesnt attach properly