De/activating Gameobject depending on distance from different Activators

So I have a UI-Button that becomes visible if the player is in a certain distance from a Activator-GameObject to activate something, let's say a door.

The Activator-GameObject has a script called Activator attached:

 public GameObject[] targets;
 private Transform player;
 private float distance;
 
 private ButtonPressed buttonActivate;
 
 void Awake () {
     player = GameObject.Find("Player").transform;
     buttonActivate = GameObject.Find("HUD").transform.GetChild(0).GetComponent<ButtonPressed>();
 }
 
 void Update () {
     distance = Vector3.Distance(transform.position, player.position);
     buttonActivate.gameObject.SetActive(distance <= activationRange);
     if(distance <= activationRange && buttonActivate.pressed)
         ToggleActivate();
 }

The UI Button has a seperate script called ButtonPressed to give the Activator-script the bool variable:

 public bool pressed;
 
 public void OnPressed () {
     StartCoroutine(x ());
 }
 
 private IEnumerator x(){
     pressed = true;
     yield return new WaitForEndOfFrame();
     pressed = false;
 }

The function OnPressed gets called by OnPointerDown from the EventTrigger-Component that starts an IEnumarator function which sets the bool pressed to true until the end of the frame to avoid staying to true all the time, because the activator-script will run ToggleActivate() every frame, so the door would be closing/opening instantly.

So, everything works as it should, but when I have 2 or more Activator-GameObjects in the game that should activate 2 different objects (light/door), the UI Button gets only visible when the player is in range of the first founded Activator-GameObject in the scene hierarchy, the other Activator-GameObjects are ignored.