Flutter中Card阴影与BackdropFilter模糊效果异常问题求助

大家好，我跟着教程视频一步步实现这个天气应用的UI，视频里的Card阴影和模糊效果都显示正常，但我完全照着操作后，效果却不对，有没有大佬能帮我看看哪里出问题了？

下面是我的代码：

class WeatherScreen extends StatelessWidget {

const WeatherScreen({Key? key}) : super(key: key);

@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
centerTitle: true,
title: const Text(
'Weather App',
style: TextStyle(fontWeight: FontWeight.bold),
),
actions: [
IconButton(onPressed: () {}, icon: const Icon(Icons.refresh))
],
),
body: Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
children: [
//main card
SizedBox(
width: double.infinity,
child: Card(
elevation: 2,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(16),
),
child: BackdropFilter(
filter: ImageFilter.blur(sigmaX: 5, sigmaY: 5),
child: const Padding(
padding: EdgeInsets.all(16.0),
child: Column(
children: [
Text(
'20 °C',
style: TextStyle(
fontSize: 32, fontWeight: FontWeight.bold),
),
SizedBox(
height: 16,
),
Icon(
Icons.cloud,
size: 64,
),
SizedBox(
height: 16,
),
Text(
'Rain',
style: TextStyle(fontSize: 20),
),
],
),
),
),
),
),
SizedizedBox(
height: 20,
),
//weather cards
Placeholder(
fallbackHeight: 150,
),
SizedBox(
height: 20,
),
//additional information
Placeholder(
fallbackHeight: 150,
),
],
),
),
);
}
}

视频里的Card阴影清晰，模糊效果也正常显示，但我这边的效果却异常，有没有人能帮我排查下原因？

备注：内容来源于stack exchange，提问作者paliokha7