Mouse events (click, cursor over, etc) does not work well on same blueprint

I create a blueprint class with a static mesh component, it can change the mesh’s material when cursor over the mesh or click it.
but, when drag my blueprint class into level, and change the static mesh to other mesh, some mesh can fire the mouse events, some mesh does not.

I checked the mesh, there is not different from other mesh that can fire the mouse events.

What’s wrong with the mesh?

Thanks.

And here is the issue video:link text

Solved, there is hidden object block the mouse event.
Sorry…