OnTriggerStay2D does not always work!

As Unity itself says:

OnTriggerStay2D is called every frame for all Collider2D.

I ran into a problem that when I stand in this area, Debug.Log starts to work for me 53 times and stops, if I move (but still stand in the area), it will work again and stops, I cannot understand what the problem is?

private void OnTriggerStay2D(Collider2D collision)
    {
        Debug.Log("Stay");
    }

https://www.youtube.com/watch?v=F8yuLvdnELI - video

Because of unity optimization(sleeping mode on rigidbody)