Bad contact shouldn't be an issue, but as the connector is overheating it is an issue. The only challenge in making a power connector is guaranteeing strong enough contact on every use. It could be caused by all sorts of things like manufacturing tolerance or exact springiness of the material of the pins.
The issue bending the cable near the connector is that it causes the connector pins to deflect, making the flimsy contact worse.
More conductor is unnecessary, it just needs to make a more reliable contact.
The issue bending the cable near the connector is that it causes the connector pins to deflect, making the flimsy contact worse.
More conductor is unnecessary, it just needs to make a more reliable contact.