Okay first found that to make the enemy mirrored, you must set the awake to true from properties panel. It work that way even without adding platformer behaviour.
EDIT
Got it! It had something to do with LineOfSight. By default LineOfSight sees only into Solid object. The Player has not Solid behaviour. So I Changed the Obstacles properties from Solids to Custom. You just need to do that and everything work just fine