The Elevator in Free Fall

The cables break and the elevator goes into free fall.
Newton told us that the elevator accelerates and, therefore, there is a
force that makes it accelerate.
Then Einstein came along and told us that this is not true and that
there is no force that accelerates the elevator in free fall.
But if there is no force that accelerates the elevator, it means that
the elevator does not accelerate.
And if it does not accelerate, then it moves with uniform speed.
But speed is not absolute: it is relative.
And so I ask: is there any reference system with respect to which its
speed is uniform?
This is for Newton's second law: force that accelerates mass.
Instead, for the first law, Einstein says that a body in the elevator
in free fall is at rest with respect to the elevator itself.
So, why does a body placed below the center of gravity of a
free-falling elevator accelerate downwards, and if it is above the
center of gravity, it accelerates upwards?
Luigi Fortunati