... I believe it's just a manufacturing defect....

This is not a manufacturing defect, but a horrible design flaw.  Putting repeated stress on the connector pin will result in the wire breaking from the pin.  I made up a wire bracket to hold the wires, but wish they had left some more slack in the wire so that I could make a proper bracket with silicon relief to prevent this.
I hope that, in future revisions, they make some  well needed changes to the cabling in this machine... along with all the quality control issues.

And now the extruder drive motor has jammed and won't turn. Instead of rotating the gear and drive shaft just makes a "thumping" noise and shift slightly back and forth.

This is both with and without filament loaded.

This machine is literally nothing but problems.

your cable on the extruder check all 4 pins wit multimeter i bet its broken
i had same problem and cable weared down not made to last

If you pull too hard, you'll pull the wire out of the pin.   In this case, if you depress the flange and press upwards at the same time on the flange, you should be able to push the pin out of the top of the connector by pushing through the little slot on the side of the connector.

If you pull too hard, you'll pull the wire out of the pin.   In this case, if you depress the flange and press upwards at the same time on the flange, you should be able to push the pin out of the top of the connector by pushing through the little slot on the side of the connector.

If you don't want to solder the wires onto the pins, you should be able to still pull the metal pin out of the white plastic connector, restrip the wire and re-crimp it onto the pin using pliers.   Then, just put it back in the same hole it came out of on the connector.

Thank you so much.

I tried pulling one out and it doesn't want to give. How did you remove the wires from the white connector?

The problem is that the connector wires are not soldered to the pins, they're just crimped on.   This compression fitting seems to come loose easily as the extruder moved back and forth.   If you don't want to solder the wires onto the pins, you should be able to still pull the metal pin out of the white plastic connector, restrip the wire and re-crimp it onto the pin using pliers.   Then, just put it back in the same hole it came out of on the connector.

My broken wire was also the left most (as you look from the front of the machine)

I removed the little metal connector from the plastic piece, and remove the wire from the metal end. This connection was very loose. I cut the wire, stripped it, and soldered the new end to the metal connector. I then inserted the connector back into the metal piece. The metal connector on mine was slightly damaged. It works, but if anyone knows what these connections are called, I would like to replace it.

Thank you so much. I have no idea what they are called... but if I find out, I'll let you know.

The thing even started sparking.

This machine is literally nothing but problems.

Mine is down for the count with the same problem and I agree... I am even considering returning it. This is a design flaw they should be seriously looking in to.

Check that the connection to the stepper is good. On mine, the leftmost wire had come out. This caused the symptoms you describe. I soldered it and its turning properly now.

Can you please tell me how you did this? I do not solder and would love to know how you did it. Did you strip the wire?

This is both with and without filament loaded.

This machine is literally nothing but problems.