My son does the same thing at all distances, obviously, it's exaggerated at further distances. His issue is target panic, instead of pulling through the shot and focusing on the center, he is coming up on the target and firing when it gets centered, by the time his brain tells him to shoot he is already past center. He is shooting a hinge as well, if I get him to focus on the shot and pull through he executes great shots. When you are missing high try to start above the target and slowly come down from above the target, if all of a sudden you start missing low then it's most likely panic.
I put a Bomar button on my bow this year and it is great for consistency, I really like it for awkward shots where its easy to move your anchor, steep downhill and uphill. I do feel like my groups have shrunk at long range using the nose button. They are pretty inexpensive as well.