Z Stepper Motor Cable extension woes

Hi I just installed the Z cable extension and the Z servo will only jitter and not turn, I connect the original curly cable to the originally supplied stepper motor cable and things work fine. I then replaced the original cable with the new extension cable all works fine.

I can join the original cable to the “new” extension cable and motor jitters again. When I add the curly cable to the extended pairs the Z axis functions properly.

To be clear in all cases I have used original as supplied Z cable that terminates into the plastic holder on the X rail. The connector on this cable appears to be compliant to the Z stepper motor as it fits, my long winded question is - are the terminations on the Z stepper different to the other stepper motors as I had no problem extending those cables?

Thanks for the response, so the cable wires are pinned differently on the “final termination end” that is good to know, and thanks for the warranty warning.

You are correct that I am indeed adding a drag chain on the X axis for Z. The reason for me doing that is because the curly cable that came with the machine got snagged on a clamp and got badly stretched, still functioning but now keeps getting caught up all the time.

Umm do you supply a dongle that will not invalidate warranty - or am I now pushing my luck LOL. Or do have to make a dongle by cutting the stretched out curly cable super short and re-terminate?

TBH you guys have almost created the perfect CNC router except for that awful curly cable or was it just beginners bad luck?!