The position.y value is not correct for ISX, and it is not consistent with the old input on UWP.

Repro:
1. Download package and project at: https://github.com/Unity-Technologies/InputSystem
2. Build UWP player for Input Test (Assets -> QA -> Input_Test -> Scenes)
3. Launch the app and the first test is Keyboard and Mouse
4. Press Ctrl + i to bring out more information
5. Observe the position for mouse between the old and new

The input affected: Mouse, Touch