Not happy with the quality and fit - Daniel Defense DD M4 Rail

Before I explain my issues with it I’ll just put this information out there, I am a long time gunsmith and builder, I was infantry in the us army and I am most knowledgeable on the ar platform. I followed all the steps and for whatever magical reason the rail would not fit tight on the upper, it was wobbling about with every movement, I spent about 3 hours watching videos and looking at the forums to see if I was missing something and the answer is no. I was expecting this to be QUALITY but it was just a waste of money. The upper I was trying to put this on now has a different rail and every component of the upper is in great condition so it wasn’t my weapon that was the issue.