Get overlapping actors returns random(ish) results?

In my game you can grab an object and drop it in another spot. While holding the actor, object collision and physics are disabled. Upon releasing the object I enable collision and try to get overlapping instances of this grass mesh, then destroy overlapping grass actors.

Above are 5 grass actors in edit view. Below is while holding the actor with collision disabled.

Once I release the object I enable collision, get overlapping actors array and destroy overlapping grass actors via for each loop. However, it always only destroys 3 of the 5 actors.

If I grab the board again and release it in the exact same spot, then one more of the actors will be detected and destroyed, and finally if i grab it again and release it one last time, the final grass actor will be destroyed. Does anyone know why get overlapping actors is only returning SOME of the overlapping actors each time it is called? Any help would be greatly appreciated.