horizontal stress only shows in the top layer

hi

i'm simulating a road using the elastic model. the road has 3 layers (asphalt, foundation, soil) with different moduli. when I apply the loads of the wheels, I can clearly see how the vertical stress continues down the different layers. the horizontal stress however is only shown in the asphalt layer. the load should cause horizontal stress in all layers of the road and it shouldn't cut of between the asphalt and the foundation.

do I have to connect the layers in the geometry or select which layers comsol calculates for or something else?

image of the horizontal stress
i.imgur.com/7XEeu0y.png

thanks
Raf Steensels