Magnitude of gravity acting on a body (mass m) is GmM/r^2, and magnitude of inertial force is ma. For vectors of two forces, to cancel each other out is not prohibited (as phenomenon). In free-falling elevator, two forces cancel each other out (as phenomenon) in one local area totally and in other local areas partially.
As above formulas show, two forces are different. Real elevator do not support equivalence principle.
