How Return Or Restart A Coroutine When A Variable Increase?

Questions & Answers
1

Hi, I have 2 scripts one for spawn second for object collision. I want when every time object collision happen level int increase and every time level int increase my coroutine restart

public class LevelManager : MonoBehaviour
{
    public static LevelManager Instance;
    public int Stage = 1;

    void Start()
    {
        StartCoroutine(StartTime());
    }
    void Update()
    {
        Levels();
    }
void Levels()
    {
        switch (Stage)
        {
        case 5:
            CannonSpeed = 24f;
            break;
        case 4:
            CannonSpeed = 12f;
            break;
        case 3:
            CannonSpeed = 6f;
            break;
        case 2:
            CannonSpeed = 3f;
            break;
        case 1:
            CannonSpeed = 1.5f;
            break;
        }
    }
public IEnumerator StartStage() 
    {
        GameObject Bullet = PoolManager.Instance.GetPooledObject();
        Bullet.transform.position = Cannon.transform.position;
        Bullet.transform.rotation = Cannon.transform.rotation;
        Bullet.SetActive(true);
        yield return null;
    }
    public IEnumerator StartTime() 
    {
        yield return new WaitForSeconds(Delay);
        StartCoroutine(StartStage());
    }

//Second Script
public class Bullet : MonoBehaviour
{
   
    void OnTriggerEnter(Collider hit)
    {
        if(hit.gameObject.tag == "Target")
        {
            gameObject.SetActive(false);
            gameObject.GetComponent<Rigidbody>().velocity = Vector3.zero;
            LevelManager.Instance.Stage++;
        }else if(hit.gameObject.tag == "Death")
        {
            gameObject.SetActive(false);
            gameObject.GetComponent<Rigidbody>().velocity = Vector3.zero;
            LevelManager.Instance.GameOver();
        }
    }


}
2

// Stops the Coroutine
yield return;

// Stops loops
break;

// Restarts the Coroutine and stops it
StartCoroutine(<IEnumerator>())
yield return;