Okay, so it seems that 3/8” is a good nock point. It could be that further reducing your nock point could reduce the nock high, but I would be reluctant to go below 3/8”. Or it could be that your nock high is a form issue. I copied this from a post I made just a short while ago on PowWow:
The following form issues can result in nock high:
1. When gripping the string split fingers, pressing down on the nock with the index finger causes a bow in the arrow shaft which rebounds when the arrow is released, often caused by high string elbow. The cure is to find a string elbow position that doesn’t result in downward pressure on the nock, and focus on drawing with the back muscles, as drawing with arm muscles can make it difficult to relax the string hand, and thus exacerbate downward pressure on the nock, among a variety of other sins.
2. When gripping the string 3 under, put most of the finger pressure on the index finger, and very little pressure on the ring finger.
Your inconsistencies in nock-right nock-left could likewise be a form issue, or you could be getting a false weak. I believe you said in an earlier post that you were usually getting a stiff indication, and a false weak is when a bare shaft that is too stiff rebounds off the strike plate and shows nock left. If you are able to find a shaft that is weak enough that it always shows weak, then you can work backwards from there.