Every picture I’ve seen has been an outside pin. So my theory is it’s the cable getting tugged for cable management and even though it’s clipped in, it’s not making as good of contact.

That or just a bad cable design. I’ve bought a few cables from cablemod and I’m not happy with the wiring they used. Their website says “Crafted with 16AWG wiring” but they also brag about the flexibility of their cables so I assume they’re using stranded wires instead of a solid core so you lose a decent chunk of ampacity (and heat sinking).