I inserted a vertex P1 at (0,0,0), then I duplicated it and I chose for the displacement of the new P2 x=+3. It did not move, why?

EASE 3.0 Only: Make sure that Room Symmetry is turned off or (if it is turned on) that the Symmetry Axis is not at x=0, otherwise a displacement moving the Vertex off the axis (in x-direction) is not allowed.