Hey! I know exactly the shot you mean, I’ve found these type of returns hard in the past myself. Good players can cut down the ball well and get some backspin on these type of returns. So you need to brush up the ball a bit more and go for more spin. If it’s very short then you might need to flick or even touch the ball back short again to wait for an easier ball to attack. A good way I have found is trying to stay low after your serve and then you can use your body and legs in the shot better to add spin and step in close to the ball when you need to if it’s short or with more backspin 🙂