I think it's both contact and wire resistance.
It is technically possible to solder a new connector on. LTT did that in a video. https://www.youtube.com/watch?v=WzwrLLg1RR4
It is technically possible to solder a new connector on. LTT did that in a video. https://www.youtube.com/watch?v=WzwrLLg1RR4