Changing the rotation of a Trigger makes the Trigger not work anymore?

I want to make it so if a player walks by a security camera, it follows the player. Thing is, changing the rotation of the camera makes the OnTriggerEnter even not fire anymore.

My code, so far, was

void OnTriggerEnter (Collider Cone) {
	if (Cone.gameObject.CompareTag ("Player")) {
		Debug.Log ("Inside");
		_playerIsSeen= true; 
}
void OnTriggerExit (Collider Cone){
	if (Cone.gameObject.CompareTag ("Player")) {
		Debug.Log ("Out");
		_playerIsSeen= false; 
	}
}
void Update (){
        if (_playerIsSeen){
              _camera.transform.LookAt(_player.transform.position);
        } else {
              _camera.transform.LookAt(_idlePoint1.transform.position);
        }
  }

The problem is, as soon as the camera moves, then OnTriggerEnter refuses to fire ever again. Either that, or OnTriggerExit keeps firing forever. The end result is that the camera snaps to the player for a millisecond before resuming staring at its default position forever, even if the player tapdances in front of it.

Fixed it, guys. It turns out that, while I had given the empty object containing the mesh a kinematic rigidbody, I had to give a kinematic rigidbody to the object that contained the empty object that contained the mesh.

I have no idea why that it is the case, but it was.

Thanks for the replies BTW.