Why walls doesn't block the pawn?

I’m quite sure that both meshes have collision mesh ( one uses SM_Cube, one uses engine default place actor cube). And they are all set to BlockAll. wall mobility is Static, paddle is a pawn set to Movable, and it paddle can still move through. If I enable SimulatePhysics of that wall, the wall will be knocked away. If I enable SimulatePhysics of paddle, paddle just can’t move.