1. turn on your PS4 by the power button, not PS4 controller.
2. connect PS4 controller to cross hair with a good and qualified USB cable
PS4 controller should be off, before connecting.
And connect G25 to cross hair.
3. then connect cross hair to PS4.
if you still can't solve it yourself,
please send a screenshot of your settings in cross hair and a video of your trouble to us.