OnMouseDown doesn't trigger sometimes

I’m using BoxCollider2Ds, all objects on scene have the same Z axis value (0).
I’m using the new unity’s pixel perfect camera controller with just 1 camera (main ortographic camera).
More than 1 collider overlapping is not the problem.

Now with the same prefab, sometimes OnMouseDown triggers perfectly,
and sometimes it just never triggers.

Is there a reason for this? Does it have to do with the fact that I’m using the pixel perfect camera?

could you link us the code so that we can have a look ? that wouuld be super helpful on figuring out why the collisions are not being detected

In the mean time, remember one of the colliding object needs to have a 2D Rigidbody since two static colliders will not collide with each other.