PS4 r2 button

This is a secondhand view since I don't have a ps4 controller, but I will say this. I have a buddy who liked playing fighting games maybe mortal combat or dragon ball z idk. but, when playing with the PS4 controller his inputs didn't work. However, using his Xbox controller it did.  do with that what you will. I can't tell you why or how to fix it, don't shoot the messenger I'm just trying to help.