Can't get the spawned boxes to move on the conveyor, cube and player worked fine.

Hello guys,

I’m new to UE and it seems I have a problem I can’t figure it out.
So here is the tutorial about making conveyor volume, I followed the tutorial step by step, but I can’t get my spawned boxes to move on the conveyor for some reason. (as shown at 14:20 in the video)
I know it can be solved by replacing the default scene root with static mesh component(Box) in the box blueprint, at least someone made it work like this and the video also had an annotation and it says: it later version of the engine you will have to set the cube as the root component by dragging it onto the defaultSceneComponent in the components panel.
Can someone please help me out with a brief explanation how to make it work.

Unreal Engine version is 4.18.3

Here is the tutorial:

Thank you