Does OnMouseDown() work for one object only at a given scene?

I have two gameObjects that when clicked on by the mouse rotate 180 degrees, the code is very simple where I used OnMouseDown() that starts a coroutine that interpolates the rotational movement. when I have one object in the scene things work perfectly, but when I duplicated my object only the original object rotates, once disabled the duplicated object works fine. what is causing the problem and what other ways to fix this?

Just make sure that:

1.) Each object has a collider and they are not overlapping

2.) Each object has a rigidbody. These can be kinematic