I wouldn't use tile movement here if I were you. Maybe MoveTo is a better choice?
+ player: Has LineOfSight to enemy
-> enemy: Set MoveTo enabled True
-> enemy: Move to player (Direct)
+ player: [X] Has LineOfSight to enemy
-> enemy: Set MoveTo enabled False
Just make sure to tweak the speed of the enemy and the player.
If you get issues with solids blocking the way, an alternative would be using the pathfinding behavior to find a path, and use the Move to behavior to move along the path using waypoints.
Hope that helps