Had a similar issue and found the rings were not aligned along the barrel saw a video of a chap flogging a metal rod on top of the rings that you aligned with the barrel, I used a piece of plastic conduit
I believe I saw the same video where he used a steel rod & grinding compound. I am a mechanic so I was determined to sort it out as I purchased the most expensive rings. My conclusion is that they are machined in the factory & are required to be put on the same way as they are machined. I did not mount my scope initially but swapping front to rear I was under 1 MOA to centre compared to only 1 MOA remaining for right windage adjustment
