There could be a few reasons for this. First, you want to make sure you do not over mix your cheesecake batter. That’s why I say only beat the eggs until incorporated and do not over mix! You also want to make sure not to over bake the cheesecake. It’s ok that it’s still a bit jiggly (just a bit!) in the middle. It will continue to bake out of the oven and then set as it cools. Last, you really want to make sure there is no sudden chance in temperature in the oven.