Pawn vehicle "sinks" into texture on component movement

First of all I’m sorry if I’m breaking any rules, this is my first question here.

I have a weird problem with my vehicle and I was hoping someone could explain what is going on.
I created the vehicle following the UE4 vehicle video tutorial, which I expanded by adding some other movable components. The problem is that after raising any of the components along the Z axis, and any movement input for the vehicle, the wheels sink into the ground, to the point of the vehicle resting on its suspension and becoming unoperable. Moving the components back into place raises the whole vehicle.

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Here’s how the component is raised in the blueprint:
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