flamethrower 2D not hitting all enemies

Hi, i have a script for the flame of my flamethrower and i've debugged all i could i'm using unity remote to test, idk if could cause this, i have a turret that fires like a flamethrower and damage target's every 0.4 seconds using ontriggerstay2d and 4 enemies in front of it, sometimes hits do not land on 1, 2 or 3 of them i've tried to check if any boxes were off at the time, or if anything was disabled and nothing so here's my code.

Code (csharp):

1.  void FixedUpdate() {
2.          if (dot_timer > 0)
3.              dot_timer -= Time.deltaTime;
4.          else
5.          {
6.              dot_timer = base_dot_timer;
7.              Debug.Log("should hit");
8.              Debug.Break();
9.          }
10.      }
11.  
12.      private void OnTriggerStay2D(Collider2D other)
13.      {
14.          if (dot_timer <= 0)
15.          {
16.              if (other.gameObject.layer == target_layer)
17.              {
18.                  Enemy_Manager enemy = other.gameObject.GetComponent<Enemy_Manager>();
19.                  enemy.Hp -= damage;
20.                  Debug.Log("hit");
21.                  enemy.Blink_fx.SetActive(true);
22.                  Vector3 screenPoint = Camera.main.WorldToViewportPoint(other.gameObject.transform.position);
23.                  bool onScreen = screenPoint.x > 0 && screenPoint.x < 1 && screenPoint.y > 0 && screenPoint.y < 1;
24.                  if (onScreen)
25.                  {
26.                      for (sbyte i = 0; i < 30; i++)
27.                      {
28.                          if (!game_manager.TextInstPool.activeInHierarchy)
29.                          {
30.                              game_manager.TextInstPool.transform.position = other.gameObject.transform.localPosition;
31.                              game_manager.TextInstPool.SetActive(true);
32.                              game_manager.TextPool.text = damage.ToString();
33.                              break;
34.                          }
35.                      }
36.  
37.                  }
38.              }
39.          }
40.      }