ImagePicker().pickVideo fr ImageSource.camera returns null (image_picker: ^1.0.0)

Question

The following code returns a null value even if I take a video with an Android Emulator Camera.

ImagePicker()
           .pickVideo(
              source: ImageSource.camera,
              maxDuration: const Duration(seconds: 3))
          .then((video) {do something to video})

Emulator Pixel 7 API 33 √ Flutter (Channel stable, 3.16.0, on Microsoft Windows Version 10.0.22631.2715, locale ja-JP) √ Windows Version (Installed version of Windows is version 10 or higher) √ Android toolchain - develop for Android devices (Android SDK version 33.0.1) √ Chrome - develop for the web √ Visual Studio - develop Windows apps (Visual Studio Professional 2022 17.1.2) √ Android Studio (version 2022.3) √ VS Code (version 1.84.2) √Connected device (4 available) √ Network resources

I confirmed that the following code worked as I expected. That means, then((video){}) returns non null data.

ImagePicker()
           .pickVideo(
              source: ImageSource.gallery,
              maxDuration: const Duration(seconds: 3))
          .then((video) {do something to video})

I have no idea why ImageSource.camera does return a null value.