Could be two things. One, very low nocking point, or two very high nocking point. Do you have a bow square? If shooting 3 under, the nock point should be around 1/2" high above square, if shooting split, only about 1/4" above (the diameter of the arrow).

You want to bare shaft tune the bow. Tear off the fletch off an arrow and shoot, from 10 paces or so. If it hits high, lower the nock point 1/32 at a time until that goes away. Then notice if it hits left or right. And cut the arrow or change point wieght to fix this until you get a lightly weak condition and your set.