Metal god, It was a PSA lower parts kit installed in a Spikes Tactical lower.
I know these companies don't actually make these parts but gets them from larger manufacturers, so I don't blame them. Both companies are A+ in my book.
There is a possibility that the trigger pin is installed wrong, but in the 3 builds I had, this is the only one that had the walking out issue and I installed all the parts the same exact way as described in many youtube videos.
Also comparing the pivot/takedown pins of the M&P and Spikes, the M&P pins are definitely tighter and harder to take out manually. the PSA pivot/takedown pins on the Spikes lower come out nicely and easily by pushing with your finger
I will verify that the spring is actually locking/catching the trigger pin and preventing it from walking out. But I hear this is a minor issue with certain AR builds which is why they sell KNS anti-walk pins to begin with. I've never seen a factory AR like a Colt or M&P with anti-walk pins, usually only builds.