Get.to(...) method returns me a black screen - FLUTTER

Question

I'm trying to use the Get package as a sort of Navigator but when I want to go to another page, the app returns me a black page, with a big X on it.

The black screen

Here the code of the main:

Widget build(BuildContext context) {
    return GetMaterialApp(
      theme: MyAppTheme.lightTheme,
      darkTheme: MyAppTheme.darkTheme,
      themeMode: ThemeMode.system,
      home: SplashScreen(),
    );
  } 

My SplashScreen: (note the startAnimation() method at the beginning, right before the Scaffold)

class SplashScreen extends StatelessWidget {
  SplashScreen({super.key});

  final splashScreenController = Get.put(SplashScreenController());

  @override
  Widget build(BuildContext context) {
    splashScreenController.startAnimation();
    return Scaffold(
      body: Obx(
        () => AnimatedOpacity(
          duration: Duration(milliseconds: 1000),
          opacity: splashScreenController.animate.value ? 1 : 0,
          child: Stack(
            children: [
              Obx(
                () =>  AnimatedPositioned(
                  duration: Duration(milliseconds: 2000),
                  top: splashScreenController.animate.value ? -20 : -30,
                  left: splashScreenController.animate.value ? -20 : -50,
                  width: 170,
                  height: 170,
                  child: Image(
                    image: AssetImage(iconaCerchioBlu),
                  ),
                ),
              ),
              Obx(
                () => AnimatedPositioned(
                  duration: Duration(milliseconds: 2000),
                  top: splashScreenController.animate.value ? 190 : 160,
                  left: splashScreenController.animate.value ? 100 : 120,
                  width: 300,
                  height: 300,
                  child: const Image(
                    image: AssetImage(iconaCerchioVerde),
                  ),
                ),
              ),
              AnimatedPositioned(
                  duration: Duration(milliseconds: 500),
                  top: 520,
                  left: 0,
                  height: 170,
                  width: 390,
                  child: Padding(
                    padding: const EdgeInsets.symmetric(horizontal: 25.0),
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          myAppName,
                          style: Theme.of(context).textTheme.displayLarge,
                        ),
                        Text(
                          myAppTagLine,
                          style: Theme.of(context).textTheme.displayMedium,
                        ),
                      ],
                    ),
                  )
                ),
              Obx(
                () => AnimatedPositioned(
                  duration: Duration(milliseconds: 2000),
                  top: splashScreenController.animate.value ? 700 : 750,
                  left: splashScreenController.animate.value ? 0 : 30,
                  child: Image(
                    image: AssetImage(iconaCerchioBlu),
                  ),
                ),
              )
            ],
          ),
        ),
      ),
    );
  }
} 

My SplashScreenController: (It should move the focus on the page to next Widget after 5 seconds, but it doesn't work)

class SplashScreenController extends GetxController {
  static SplashScreenController get find => Get.find();
  RxBool animate = false.obs;

  Future startAnimation() async {
    await Future.delayed(Duration(milliseconds: 500)); //0.5s
    animate.value = true;
    await Future.delayed(Duration(milliseconds: 5000));
    Get.to(() => WelcomeScreen());
  }
} 

And the Welcome() page:

Widget build(BuildContext context) {
    return Placeholder(
      child: Text(
        "Ciao, sono la schermata Home",
        style: Theme.of(context).textTheme.displayMedium,
      ),
    );
  } 

I've already tried to use Get.to( () => WelcomeScreen() ) instead of what I've put in the code above.

Have you got and idea of the reason of that? Thanks!