How to make enemy chase player on X and Y coordinates?

I am trying to create a function to make enemy chase the player on my game. The player moves on X and Y coordinates and the enemy needs to chase on X and Y coordinates as soon as the player change his coordinate. To do this I am trying the function below but it still does not working on Y coordinate. The X works so well but in Y coordinate enemy does not moving on player position.

How could I do it ?

var _can_attack = false
var _collision_weapon_default_positionX:float
var _raycast_default_rotate_position:float
var _player_ref:Player
var _enemy_direction:Vector2 = Vector2.ZERO 
var target_position

func _physics_process(delta: float) -> void:
    enemy_attack()  
    _flip_me()
    _enemy_move()   
    
func _enemy_move() -> void:
    var x_direction = sign(_player_ref.global_position.x - global_position.x)
    var y_direction = sign(_player_ref.global_position.y - global_position.y)
    _enemy_direction = Vector2(x_direction, y_direction).normalized() * speed
    velocity = _enemy_direction
    move_and_slide()
        
func _flip_me() -> void:
    if(_player_ref.global_position.x > global_position.x):
        animated_sprite.flip_h = false
        collision_shape_2d_attack.position.x = _collision_weapon_default_positionX
        ray_cast_2d.rotation = _raycast_default_rotate_position
    elif(_player_ref.global_position.x < global_position.x):
        animated_sprite.flip_h = true
        collision_shape_2d_attack.position.x = -_collision_weapon_default_positionX
        ray_cast_2d.rotation = -_raycast_default_rotate_position

Done. I just changed the reference of player(characterbody2D) position to getting the CollisionShape2D of player and did the same on enemy and it works so well. Before did it I was getting the reference of Character2D and it does not working because the Y coordinate was very so far each other. Now it works as I wanted

I did

func _enemy_move() -> void:
    var _player_collision:Vector2 = _player_ref.get_collision_shape_2D_position()
    var x_direction: float = sign(_player_collision.x - collision_shape_2d.global_position.x)
    var y_direction: float = sign(_player_collision.y - collision_shape_2d.global_position.y)
    _enemy_direction = Vector2(x_direction, y_direction)
    velocity = _enemy_direction * speed     
    move_and_slide()