Vertex Displacement works on one model but not another.

I purchased a nature pack from the asset store. It contains a material and a shader that makes the included meshes look like they are swaying in the wind. Later I bought another pack from the same asset developer and dragged the material onto one of the new models. It does NOT sway in the wind. Why do the two models with the same material not produce the same vertex displacement effect? I tried fiddling with the mesh import settings. I tried importing the model into blender and adding uv maps. Neither worked.