It could be a nutrition, soil pH issue or some other kind of stress(clone, reveg, transplant, light stress, environmental stress) I had something similar happen to me 2 grows back. I had a Tangie that was in very hot soil. She was getting nitrogen toxicity and a calcium deficiency at the same time. Throughout the whole grow I noticed that each and every leaf only had 3 fingers on it. I also noticed plants that are really healthy can have up to 9 points!
My current grow experienced some transplant shock and you can see on the MAC where the experienced the shock because she's got 2 sets of 3 pointed leaves with purple stems while the leaves above look healthier and have 5 points.
If it doesn't improve and new leaves keep growing only 3 points, you have to see about other possible stressors. If new leaves grow up healthy then you have nothing to worry about.