BZT - A Poor Quality Machine

[DuffelBuffelWuffel]

anyway saw the video , could you check at what speed the communication is set in usbCNC ? 125Khz is the fastest and that is what is generally used (settings tap) Less might be not enough bandwidth or something like that.. It is probably in the manual.
I would just check and see what happens, this is all PC sided anyway, nothing bad can happen.

Check the voltage going to the stepper motor, check the microstep settings and the current limit of the driver.
This looks simular:
https://www.youtube.com/watch?v=vg1p99FGUXA
User had provided 1.3v instead of 3 for his stepper motor.
-Does your pc meet the required specs for Eding CNC ?

These seem to be normal stepper motors so not much can actually go wrong.
Can the drivers be tuned in any way ?

You might also want to check the powersupply voltage while the motor is runing. It might be dipping because of some defect.