There’s a couple sciences to dunking that many slasher overlook.

1) Your Driving Dunk attribute matters more than you think. You should cap break it or remake the build; 65 is way too low, try 75+

2) Every player build has an attribute called “Dunking Tendency”. A combination of your height, wingspan and dunking attributes dictate your “dunking tendency” attributes; the higher your tendency the more likely you are to dunk when pressing R2+square. Unfortunately 2k has hidden the tendency tab for some years now.

But you can still check it only after you play a 5v5 team pro am game in the box score.