If the motor is not working well, please open the ESC case to make sure all wires are connected well.
Then follow below technical support video to swap the motors cables.
https://youtu.be/XZOZiAc_SQ0 （For new ESC）
https://www.youtube.com/watch?v=RmlRqBm2gt8 (For old ESC）
Please share the motors performance video BEFORE & AFTER swapping, as your test video is a MUST for us to arrange accessory replacement under warranty.
You might share the video via G Drive, Dropbox or YouTube private video to firstname.lastname@example.org
(If YouTube, please choose "Unlisted")
After swapping the cable, there are 3 possible results:
1. The same motor not works. Then you need a new motor.
2. The other motor not works, then you need a new ESC.
3. Both motors not work, then please check if the cables are connecting into the right place.