actions dont execute after waitforseconds

Hello, i have no idea why actions dont execute after yield return new WaitForSeconds(5).
in consol i can see 0, but after 5 second or more for example ,2" isn’t showed. Any suggestion? Many thanks.

public IEnumerator continue()
{        
    if (sc.wykorzystana == true)
    {
        gameover();
    }

    if (sc.wykorzystana == false)
    {            
        Debug.Log("0");
        yield return new WaitForSeconds(5);
        secondcha.SetActive(true);                      
        Debug.Log("2");
        if (sc.szansa == 0)
        {
            secondcha.SetActive(false);
            gameover();
        }
    }

Check the gameobject and script are enabled. If you disabled some of them, then the coroutine will stop.