Flutter: flutter_launcher_icons generates deformed icon

Question

I am using flutter_launcher_icons (0.11.0) to generate my launcher icons. Unfortunately, the result for Android is always deformed:

It works fine on IOS:

Here is my config:

flutter_icons:
  android: true
  image_path_android: "assets/icons/android/background.png"
  adaptive_icon_background: "assets/icons/android/background.png"
  adaptive_icon_foreground: "assets/icons/android/foreground.png"
  ios: true
  image_path_ios: "assets/icons/ios/iconx1024.png"
  min_sdk_android: 21

Here are the dimension of the images I used (imgur):

background.png (512x512)
foreground.png (390x390)
// For IOS I am using a combined image:
iconx1024.png (1024x1024)

I am testing on an emulator (Pixel 3 API 31). I have tried going the "native route" by just copying the images from icon.kitchen and that works. However, I am under the impression that this should not be necassary with flutter_launcher_icons.

How do I make the Android icon work properly with flutter_launcher_icons ?