If the D-pad on your SCUF Infinity4PS PRO is not functioning as expected, try resetting the controller with the following steps:  

1. Turn off the PlayStation 4 console.
2. Locate the small reset button hole on the back of the SCUF Infinity4PS PRO near the L2 shoulder button.
3. Use a small, unfolded paper-clip or something similar to push the button (the button is inside the tiny hole). Hold the button down for a 2 - 3 seconds and release.
4. After resetting the controller, re-pair the SCUF with the PlayStation console by connecting the USB cable to the controller and the system, and turning the PS4 console on.  
5. Press the PS button on your controller to log in to the PS4.