Stepper motor Slightly toggling during revolution

Using Arduino Project Guidance
1

I have a Nema23 Stepper motor which I have connected using a DM542 Stepper Driver. I supply it a current of around 3Amps and have set the step value to 1/8th of a full Step. While I am rotating the entire assembly using the stepper motor as shown in the video link attached below , it seems to be stopping with a sudden jerk .

Here is a video showcasing the Issue , as soon as the rotation is about to complete , one can see that it stops with a sudden jerk/rebound , i want it to stop in a smooth manner

#include <Servo.h> //Servo library
// Pin Definitions
#define dirPin 2   // Direction
#define stepPin 3  // Step Pulse
#define enaPin 4   // Enable Motor
// #define STPR 200   // Steps per Revolution

 
Servo myservo; //Servo name is myservo

// Variables
int stepDelay = 1250; // Delay between steps in microseconds
int stepsToMove = 20; 
 
 
void setup() {
Serial.begin(9600);
// myservo.attach(9); // attaches the servo signal pin on pin D6
// Set pin modes
  pinMode(enaPin, OUTPUT);
  digitalWrite(enaPin, LOW); // Enable motor
  
  pinMode(dirPin, OUTPUT);
  pinMode(stepPin, OUTPUT);

 
}
 
void loop() {

  // myservo.write(160); //Turn clockwise at high speed
  // delay(3000);

  // myservo.write(40);
  // delay(3000);

digitalWrite(dirPin, LOW); // Set direction to clockwise
 for (int i = 0; i < stepsToMove; i++) {
    digitalWrite(stepPin, HIGH);
    delayMicroseconds(20);
    digitalWrite(stepPin, LOW);
    delayMicroseconds(stepDelay - 20);
  }
  delay(3000); // Delay for 1 second

}

Any Ideas why the stepper is stopping in this manner , I tried playing around with different current values as well as different mini steps and also tried reducing the rmps but l but nothing seems to fix it.
Any help would be greatly appreciated.

2

This is a mechanical problem due to the abrupt stopping of the stepper and the inertia of the disc. You need to smoothly decelerate the stepper and not stop it abruptly.
You need a stepper library that supports acceleration/deceleration like AccelStepper or MobaTools.
Which board are you using ( Looks like an UNO )?