Collider problem help

My Player is getting collided without and collision. Can not detect the problem. can you help?

private void OnControllerColliderHit(ControllerColliderHit hit)
{
if (hit.point.z > transform.position.z + playerController.radius)
{
GameOver();
Debug.Log(“Death on collision”);
}
}

private void GameOver()
{
    isGameOver = true;
    Debug.Log("Dead");
    GetComponent<Score>().OnGameOver();
}

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You have to test the tag name, if the object has not the tag name Ground you can execute the Game Over