Locking pin is too large for commercial tube - BlackHawk Knoxx Axiom A-Frame Carbine Stocks

The locking pin inside the stock is too large to engage with the notched position settings of my commercial buffer tubes. In fact, I could not find a buffer tube that this stock actually worked with. I returned it for a replacement and had the same issues. Im perplexed that this issue is not more popular considering it seems as if this is a major design flaw.