This seems to be a common problem, judging by the YouTube videos and posts at OS, and depending on your Archetype, one of the patches seems to have addressed it. However, I'm still having the issue: I can rarely get my Sharpshooting Playmaker point guard to dunk in MyCAREER, in situations where he definitely should be dunking.
I've tried this suggested fix:
...but to no avail. Dunk packages are definitely equipped, and with all the grinding, I've managed to get my Driving Dunk rating up to 57 (Standing Dunk 46, Contact Dunk 55), which has allowed me to buy and assign a few more flashier packages. I also have my Vertical rating up to 72, and have tried using both the Pro Stick and the Shoot button, making sure I have enough sprint. Same issue; I can't consistently dunk in situations where my player should, and situations where I see other Sharpshooting Playmakers dunking in 2K Pro-Am.
Obviously, it's not an Archetype that should be dunking over anyone and everyone at will - that's something for the Slasher and Slasher hybrid Archetypes to enjoy - but again, compared to other players with the same build, in situations where I should be dunking, the game is not letting me throw down. It's mostly a Pro-Am and MyCAREER issue as I can dunk a little more often in The Playground (I even finished an alley-oop someone threw me the other day!) and there are no problems whatsoever when shooting around on MyCOURT.
Anyone else experiencing similar issues? Any further advice? As I said, the fix mentioned above didn't work. It looked as though it might have after hitting The Playground, but still the same story in MyCAREER. I also do have a few more upgrades I can make to Dunks and Vertical, though I need to keep grinding the level caps to get them at this juncture.