When I use the Colorimeter Window to measure the black of my screens, it doesn’t change at all between measurements. Is it frozen?
SpyderX measures much more effectively in the darks than previous Spyders. At white, the screen will vary a bit, so the Cap Y (screen brightness) value will move tiny amounts between measurements. But at black, the screen is much more consistent, and so the Cap Y (and all the other values) tend to remain the same.