Why doesn't my mesh scale in game(when playing)?

I have a mesh and BP made out of it. In the blueprint I scaled down the mesh, compiled, saved, but when I press play, the mesh is at it’s original siz, without the scaling I’ve done on it.

Why is that?

After creating the BP, add a Scene Component. Then parent that mesh to the Scene component. In the list at top left corner, hover over the Scene Component with your mouse, hold left click and drag it over the Mesh component. It will show up a note “Make new Root” and you will see the Scene is at top, and mesh is below. Now try to scale your mesh.

The problem is, I cannot make a new blueprint, as the one I’m wokring with has already a lot of graphs. I tried to put a scene component in it anyway, but when I dragged it on the mesh, it said that it cannot be set to root as Blueprint is inherited.