Why is the timer not working?

Question

Unity

What's wrong?

IEnumerator SpawnMobs()
    {
        Debug.Log(ThisZombieSpawn);
        Debug.Log(CountZombieSpawn);

    if (ThisZombieSpawn < CountZombieSpawn)
    {
         Instantiate(ZombieType[NomberZombie], StartPos.position, Quaternion.identity);           
         yield return new WaitForSeconds(4); // доходит до сюда и дальше тишина... 
          ThisZombieSpawn++;
         SpawnMobs();

    }

    }

Answer 1

In the start method or wherever you need it, you most likely did not write StartCoroutine(SpawnMobs())

Answer 2

Should it be a looped coroutine?
At the end, do you call the SpawnMobs method, or did you mistakenly decide to start the coroutine again?