Driving rotation with shrinkwrap (not working)

Hi. I am driving a rotation of a mesh with a shrink-wrapped (z position) surface to the ocean.
If I multiply the expression by any number my mesh rotates. But when I animate the ocean and my shrink-wrapped surface moves, the driven mesh does not move.

Unfortunately, I can not share the scene. I could make a mockup scene. Do you know what am I missing?

Thank you