I have a problem. I am following this guide about controlling a NEMA 17 stepper motor: https://www.makerguides.com/a4988-stepper-motor-driver-arduino-tutorial/
I uploaded the code to my arduino uno and powered on everything, but the stepper motor doesn't rotate, except when I put my finger on the metal screw of the a4988 driver. The arduino is powered by a 5v 1A adapter and the a4988 driver is powered with a 12v 2amp adapter.
What is causing this?