My GameObject is not moving when the camera is not looking at it

I have a game where the camera is pretty far away from objects, lets say about 500 units away. These enemy game objects are randomly spawned at timed intervals. This works just perfectly without the need for the camera to be looking at the objects. But the enemy objects that are spawned are supposed to be moving to a defined target, but they aren't moving unless the camera has seen them first.

In other words, if you don't understand already, my enemy objects that are spawned off camera will not move toward a defined target until the camera puts them in view. When that happens the object will move towards the defined target just fine.

So, is this a known issue, or what?