Need help with my Move Code.

Hi All.
i want my Gameobject to move smoothly to the waypoint.

If i change the code so i use a Letter Like "A" then it works. but then i use Buttons. it will not go smoothly to the waypoint. but it jumps a bit. and then i press again it jumps a bit more, until it hit my waypoint.
how does i make the buttonpress move smoothly.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;

public class WaypointMove : MonoBehaviour
{
public Button button1;
public GameObject[] waypoints;
int current = 0;
float rotspeed;
public float speed;
float WPradius = 1;

void OnEnable()
{
button1.onClick.AddListener(() => buttonCallBack(button1));
}

// Update is called once per frame
private void buttonCallBack(Button buttonpressed)

{
if (Vector3.Distance(waypoints[current].transform.position, transform.position) < WPradius)
{
current++;
if(current >= waypoints.Length)
{
current = 0;
}
}

transform.position = Vector3.MoveTowards(transform.position, waypoints[current].transform.position, Time.deltaTime * speed);
}
}