why Child transformation doesn't follow parent transformation?

Hi, I created a blueprint class base pawn.
The problem I have is that when I move one of the component of this class, its children don’t follow its transformation.
see picture below where I have a skeletal mesh (the bike) and it has a spring arm and camera as shown in the hierarchy.

then now in the picture below,


I move the skeletal mesh(Bike).

as you see, when I move it upside, the spring arm and camera doesn’t follow it.
I am confused, I expect that because the spring arm and the camera are the child of this skeletal mesh, then when I move the skeletal mesh, they should move with it. NO?

What is the issue.
Thanks.

In the Details panel, make sure your spring arm’s transforms are set to Relative, not World.