Why is my multi touch not working?

maybe there are other ui elements your finger is clicking?

if you are trying to read more than 1 touch by frame (ie screen touch and joystick touch at the same time) you need to iterate trough the array of input touches

  for (int i = 0 ; i < Input.touchCount ; i++){
      //change all Input.touches[0] by Input.touches[i] inside the if 
      //(is your first if without the Input.touchCount > 0) 
      if (Input.touches[i].phase == TouchPhase.Began)
      {
          if (!EventSystem.current.IsPointerOverGameObject(Input.touches[i].fingerId))
          {
              if (!anim.GetCurrentAnimatorStateInfo(0).IsName("PlayerAttack"))
              {
                  anim.Play("PlayerAttack");
              }
          }
      }