Lack of fluidity in the game despite high fps in unity

In my 2D game there is a wheel rotating on its own axis in which I noticed that after high fps it does not spin smoothly. it is not a big difference but after some time it starts to annoy me. I also tried to change something in the game settings but it didn’t help. i don’t know what the problem is.
this is my script to

using System.Collections;
using UnityEngine;

public class LogRotation : MonoBehaviour

    [System.Serializable] //this will allow us to edit it in the editor
    //a custom class representing a single rotation "element" of the log's rotation pattern
    private class RotationElement
        //to get rid of an obnoxious warning about these fields not being initialized
#pragma warning disable 0649
        public float Speed;
        public float Duration;
#pragma warning restore 0649

    [SerializeField] //attribute making private fields editable in the Unity Editor
    //the aforemention full rotation pattern of the log
    private RotationElement[] rotationPattern;

    //this will be set to the Wheel Joint 2D from the LogMotor object
    private WheelJoint2D wheelJoint;
    //something has to actually apply a force to the log through the Wheel Joint 2D
    private JointMotor2D motor;

    private void Awake()
        //setting fields
        wheelJoint = GetComponent<WheelJoint2D>();
        motor = new JointMotor2D();
        //starting an infinitely looping coroutine defined below right when this script loads (awakes)

    private IEnumerator PlayRotationPattern()
        int rotationIndex = 0;
        //infinite coroutine loop
        while (true)
            //working with physics, executing as if this was running in a FixedUpdate method
            yield return new WaitForFixedUpdate();

            motor.motorSpeed = rotationPattern[rotationIndex].Speed;
            //hard coded 10000, feel free to experiment with other torques if you wish
            motor.maxMotorTorque = 10000000;
            //set the updated motor to be the motor "sitting" on the Wheel Joint 2D
            wheelJoint.motor = motor;

            //let the motor do its thing for the specified duration
            yield return new WaitForSecondsRealtime(rotationPattern[rotationIndex].Duration);
            //infinite loop through the rotationPattern
            rotationIndex = rotationIndex < rotationPattern.Length ? rotationIndex : 0;


and these are the elements from the inspector:

Try to enable interpolation on your Rigidbody. Currently its transform is updated only at the rate of physics / fixed update.

You could, of course, not use rigidbody and motor at all, and simply rotate the wheel in the Update. That is, if you don’t actually need any physics interaction with the wheel