Isn't that what it's supposed to do in the middle of a corner when you hit the gas? Unless you apply enough throttle to break the back loose, mild understeer leading out of a corner is where you want the car to go. The Porsche is a rear-engine layout so the back has a tendency to want to come around easier than a mid-engine layout which is why it wouldn't elicit understeer as easily.
By default, the factory is going to dial in a bit of understeer just for safety since not all customers are track experienced. You can change the settings yourself if you want to dial in more oversteer.