Prevent fullscreen break when loading scene (#3828)

ui/v2.5/src/components/Scenes/SceneDetails/Scene.tsx

@@ -541,6 +541,17 @@ const SceneLoader: React.FC = () => {
   const { configuration } = useContext(ConfigurationContext);
   const { data, loading, error } = useFindScene(id ?? "");
 
+  const [scene, setScene] = useState<GQL.SceneDataFragment | undefined>(
+    data?.findScene ?? undefined
+  );
+
+  // only update scene when loading is done
+  useEffect(() => {
+    if (!loading) {
+      setScene(data?.findScene ?? undefined);
+    }
+  }, [data, loading]);
+
   const queryParams = useMemo(
     () => new URLSearchParams(location.search),
     [location.search]
@@ -752,14 +763,15 @@ const SceneLoader: React.FC = () => {
     }
   }
 
-  if (loading) return <LoadingIndicator />;
+  if (!scene && loading) return <LoadingIndicator />;
   if (error) return <ErrorMessage error={error.message} />;
 
-  const scene = data?.findScene;
+  if (!loading && !scene)
-  if (!scene) return <ErrorMessage error={`No scene found with id ${id}.`} />;
+    return <ErrorMessage error={`No scene found with id ${id}.`} />;
 
   return (
     <div className="row">
+      {scene && (
         <ScenePage
           scene={scene}
           setTimestamp={setTimestamp}
@@ -778,6 +790,7 @@ const SceneLoader: React.FC = () => {
           setCollapsed={setCollapsed}
           setContinuePlaylist={setContinuePlaylist}
         />
+      )}
       <div className={`scene-player-container ${collapsed ? "expanded" : ""}`}>
         <ScenePlayer
           key="ScenePlayer"