Flutter Notification shows as shadow/gray

I'm using Firebase as my notification handler and the notification image works well with IOS. For some reason, in some android devices the notification image appears to show the shape of the logo but just gray.

So far this is what I've tried:

1. Used mipmap and drawable as my meta-data resource in the AndroidManifest.xml

2. Created /android/app/src/main/res/raw/keep.xml

   <?xml version="1.0" encoding="utf-8"?> <resources xmlns:tools="http://schemas.android.com/tools" tools:keep="@drawable/*" />

3. Ensured that the notification image is transparent.