Ok.....here's the deal. We can't see you shoot. so that being the case, every bit of information that you get, is assumption.
We don't know what kind of bow you're shooting, we dont what kind of arrows you are shooting, we don't know what kind of alignment you have. What distance you're shootng at, nothing.
Now, that being said, in my opinion, trying to move vertical impact that much, using brcae height, is a fools errand. Cutting the arrows, well, that will stiffen them. IF they are stiff to begin with and it's not your alignment. I don't let arrows dictate what length I cut them. I cut the the length I want them and then make 'em shoot.
Rather than trying to find soemthing wrong with the equipment, concentrate on getting straight in line behind the arrow, Point it from the string, through the point at the target and try that. If you are canting your bow, stop until you get closer to being in the ballpark.
Shoot the arrows at a vertical line on the target. See how they group then. You should have the ENTIRE arrow pointed at the target when you shoot. After you do that, the access your arrow flight and come back with pertinent details.
