Model has been RIGIFIED and skinned but only legs & Torso respond, not other Shapes

I have fitted RIGIFY’s metarig onto a model, then generated the Shapes (all nice), then Skinned the mesh to the rig.

I then waited breathlessly for the mesh to respond to moves (G or R) from the Shapes.
The legs (ik) move fine and so does the Torso. But the mesh refuses to budge for the other Shapes (head, neck, arms, spine, hips).
So why do only some of the Shapes respond and not the rest?
Please help.