fix timing menu bug

Assets/Src/UI/ShipUi.cs

@@ -6,8 +6,7 @@ using UnityEngine;
 using UnityEngine.UIElements;
 
 public class ShipUi : MonoBehaviour {
-    [SerializeField]
-    UIDocument uiDocument = null;
+    UIDocument uiDocument;
 
     [SerializeField]
     ShipControls ship;
@@ -20,7 +19,12 @@ public class ShipUi : MonoBehaviour {
     VisualElement sectors;
     VisualElement timeSheet;
 
-    void Awake() {
+    void OnEnable() {
+        Init();
+    }
+
+    void Init() {
+        uiDocument = GetComponent<UIDocument>();
         speed = uiDocument.rootVisualElement.Q<Label>("speed");
         timer = uiDocument.rootVisualElement.Q<Label>("timer");
         sectors = uiDocument.rootVisualElement.Q<VisualElement>("sectors");
@@ -30,7 +34,7 @@ public class ShipUi : MonoBehaviour {
     void FixedUpdate() {
         if (timer == null || speed == null) {
             Debug.LogWarning("no speed or timer");
-            Awake();
+            Init();
             return;
         }