I have just bought a decent GPU (MSI GeForce GTX 1660) which has an 8-pin connector. My PSU ( Seasonic S12II Bronze 620W ATX 12V) has a 6-pin connector (which easily connected to my old GPU) and an 8-pin connector which struggled mightily to even get a small snug into my new GPU connector. I backed off since there's no way it should be that hard to plug in this 8-pin connector. What am I not seeing here? Any help would be very appreciated!!!