Hi,
I tried the same example which Ben teaching in this video, but for me during autoplay ball and paddle together moves toward right automatically and stops at the right wall. Then after clicking to start it works properly after that.
Check the collider on your paddle. If the top is not a straight flat line it will do that. I had to go back and edit my collider again because the same thing happened to me, only mine went to the left. After I adjusted the collider it works perfectly. Hope this helps.