Lap Counter Bug

Hello! I have a bug in the UI Script. After I completed the first lap, it's stuck in the first lap, and after I completed the third lap, the race is finished. Anybody can help me with this bug?

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class UIScript : MonoBehaviour
 {
     GameObject Player;
     public GameObject missedCheckpointText;
     public GameObject pauseGameMenu;
     public Text positionText;
     public Text lapText;
     Checkpoints checkpoint;
     public Text finalPosText;
     public Text earnedCoinsText;
     RaceManager raceManager;
 
 
 
     void Start()
     {
         Player = GameObject.FindGameObjectWithTag("Player");
         checkpoint = Player.GetComponent<Checkpoints>();
     }
 
     void Update()
     {
 
         if(checkpoint.checkPoint == 0 )
         {
 
             lapText.GetComponent<Text>().text = "Lap: " + checkpoint.lap + "/" + raceManager.maxLaps;
 
         }
         positionText.GetComponent<Text>().text = "Position: " + CalculatePositions.getPositions(Player.name);
         if (Player.GetComponent<Checkpoints>().missed==true)
         {
             StartCoroutine(showmissedCheckpointtext());
             Player.GetComponent<Checkpoints>().missed = false;
         }
 
         if(Input.GetKeyDown(KeyCode.Escape))
         {
             PauseGame();
         }
 
     }
 
     IEnumerator showmissedCheckpointtext()
     {
         missedCheckpointText.SetActive(true);
         yield return new WaitForSeconds(2);
         missedCheckpointText.SetActive(false);
     }
 
     public void PauseGame()
     {
         pauseGameMenu.SetActive(true);
         Time.timeScale = 0;
     }
 
     public void ResumeGame()
     {
         Debug.Log("Btn Clicked");
         Time.timeScale = 1;
         pauseGameMenu.SetActive(false);
     }
 
     public void showFinalPos()
     {
         if(CalculatePositions.getPositions(Player.name)=="1st")
         {
             int currentCoins = PlayerPrefs.GetInt("coins");
             PlayerPrefs.SetInt("coins", currentCoins + 750);
             earnedCoinsText.text = "You earned 750 coins";
         }
         else
         {
             int currentCoins = PlayerPrefs.GetInt("coins");
             PlayerPrefs.SetInt("coins", currentCoins + 100);
             earnedCoinsText.text = "You earned 100 coins";
         }
         finalPosText.text = CalculatePositions.getPositions(Player.name);
 
     }
 
 
 
 
 }