When inserting the pins in to the connector. I had issues too. Look close. They only go in one way. My pins were 4 sided and I got it wrong 3 of the 4 tries
till I figured how they fitted . Also I had two pins with to much solder on them. I had to pinch the end with the wire with pliers to make it not as wide and to remove the hanging solder and make it fit in the hole. Don't give up. It's well worth the time you put in to it.