Why does my button only work once?

Hey, I'm using unity's new UI Builder and toolkits so there's not a lot of info on the topic. But I have all buttons working and functioning like they should, except every button on every gameobject (setting layers) works only once. Any help appreciated.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.SceneManagement;
 using UnityEngine.UIElements;
 
 public class UI_input_manager : MonoBehaviour
 {
     public Button buttonSingle;
     public Button buttonMulti;
     public Button buttonSettings;
     public Button buttonAbout;
     public Button buttonQuit;
 
 
     public GameObject About;
     public GameObject Setting;
     public GameObject Home;
     
 
     void Start()
     {
 
         var root = GetComponent<UIDocument>().rootVisualElement;
 
         buttonSingle = root.Q<Button>("singleplayer");
         buttonMulti = root.Q<Button>("multiplayer");
         buttonSettings = root.Q<Button>("settings");
         buttonAbout = root.Q<Button>("about");
         buttonQuit = root.Q<Button>("quit");
        
         buttonSingle.clicked += StartSingle;
         //buttonMulti.clicked += StartMulti;
         buttonSettings.clicked += OpenSettings;
         buttonAbout.clicked += ShowAbout;
         buttonQuit.clicked += QuitGame;
     }
     
     void StartSingle()
     {
         SceneManager.LoadScene(2);
     }
 
     void QuitGame()
     {
         Application.Quit();
         Debug.Log("Exit game");
     }
 
     void OpenSettings()
     {
         Home.SetActive(false);
         Setting.SetActive(true);
     }
 
     void ShowAbout()
     {
         About.SetActive(true);
     }
 
     }