Pong game issue with ball

Python
1

Was following this tutorial but the ball has a strange behaviour when it gets to the top of the screen (it just hangs along the top border).
But also this like has been throwing errors ball.setx(ball.xcor() + ball.dx)

import turtle

wn = turtle.Screen()
wn.title("pong")
wn.bgcolor("white")
wn.setup(width=800, height=600)
wn.tracer(0)


ball = turtle.Turtle()
ball.speed(10)
ball.shape("circle")
ball.color("black")
ball.penup()
ball.goto(100, 0)
ball.dx = 2 
ball.dy = -4 

while True:
    wn.update()      

    ball.setx(ball.xcor() + ball.dx)
    ball.sety(ball.ycor() + ball.dy)


    if ball.ycor() > 290:
       ball.sety(290)
       ball.dy *= 1
     
    
    if ball.ycor() < -290: 
       ball.sety(-290)
       ball.dy *= -1
      

    if ball.xcor() > 390: 
       ball.goto(0, 0)
       ball.dx *= -1
     
       
    if ball.xcor() < -390: 
       ball.goto(0, 0)
       ball.dx *= -1
2 
ball.dy = -2