The problem with GetChildrenComponents()

Hey. I create the actor, adding to his cube, do it physically, then in the constructor function call GetChildrenComponents and writes the results into an array. 2 shows the array element - right. Then I try to do the same thing in C ++: constructor RootComponent-> GetChildrenComponent (true, ArrayChildren). I pass to the editor, conscious cube, do it physically. However, the array elements 0! Why? If the cube does not do the physical, it shows an element 1 - true. Tell me, please, what to do?