Disable with stack widget.

I just set widget like this.

Scaffold(
body: Stack(
children: [
Align(
alignment: Alignment.center,
child: SafeArea(
left: Platform.isAndroid ?? true,
top: Platform.isAndroid ?? true,
right: Platform.isAndroid ?? true,
bottom: Platform.isAndroid ?? true,
child: WebviewScaffold(
key: _shopViewKey,
primary: false,
hidden: true,
withOverviewMode: true,
initialChild: Container(
width:size.width*1,
height:size.height*1,
color:Colors.white,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Image.asset(
'assets/p_red_logo.png',
fit: BoxFit.cover,
width: mw(190),
height:mw(50),
),
Padding(
padding: EdgeInsets.only(top: mw(19), bottom: mw(20)),
child: SizedBox(
width: mw(26),
height: mw(26),
child: CircularProgressIndicator(
valueColor: new AlwaysStoppedAnimation(Color(0XFFec3e39)),
),
),
),
Padding(
padding: EdgeInsets.only(bottom:mw(20)),
child: Text('쇼핑몰로 이동중이에요!', style: TextStyle(fontSize: ScreenUtil().setSp(16), fontWeight: FontWeight.w900),),
),
Text('피클링에서 제공하는 상품정보는', style: TextStyle(fontSize: ScreenUtil().setSp(12), fontWeight: FontWeight.w500, color: Color(0XFF8a8a8a)),),
Text('쇼핑몰과 일치하지 않을 수 있습니다.', style: TextStyle(fontSize: ScreenUtil().setSp(12), fontWeight: FontWeight.w500, color: Color(0XFF8a8a8a)),),
Text('방문한 쇼핑몰에서 반드시 상품정보를 확인해주시기 바랍니다.', style: TextStyle(fontSize: ScreenUtil().setSp(12), fontWeight: FontWeight.w500, color: Color(0XFF8a8a8a)),),

Padding(
padding: EdgeInsets.only(top: mw(10)),
child: Text('(주)마들렌메모리는 통신판매의 당사자가 아니며,', style: TextStyle(fontSize: ScreenUtil().setSp(12), fontWeight: FontWeight.w500, color: Color(0XFF8a8a8a)),),
),
Text('상품에 대한 주문 및 배송, 환불 등에 대한 의무와 책임은', style: TextStyle(fontSize: ScreenUtil().setSp(12), fontWeight: FontWeight.w500, color: Color(0XFF8a8a8a)),),
Text('해당 쇼핑몰에 있습니다.', style: TextStyle(fontSize: ScreenUtil().setSp(12), fontWeight: FontWeight.w500, color: Color(0XFF8a8a8a)),),

],
),
),
supportMultipleWindows: true,
withJavascript: true,
debuggingEnabled: true,
resizeToAvoidBottomInset: true,
useWideViewPort:true,
url: Uri.encodeFull(widget.viewData[0]),
),
),
),
_visible == true && _isMarked == true ?
Positioned.fill(
child: FadeTransition(
opacity: Tween(begin: 0.0, end: 1.0).animate(animationController),
child: ScaleTransition(
scale: Tween(begin: 0.5, end: 1.5,).animate(CurvedAnimation(
parent: animationController,
curve: Curves.elasticOut,
reverseCurve: Curves.fastOutSlowIn
)),
child :Icon(Icons.favorite, size: mw(100), color:Color(0XFFed3d47),)
),
)
): Container(),
Positioned(
top:mw(20),
left:mw(20),
child: Container(color:Colors.blue, width: mw(100), height:mw(100)),
)
],
),
bottomNavigationBar: BottomNavigationBar(
currentIndex: _bottomSelectedIndex,
selectedItemColor: Colors.black,
unselectedItemColor: Colors.black,
showUnselectedLabels: true,
type: BottomNavigationBarType.fixed,
onTap: (index) {
bottomTapped(index, $user, $item, context);
},
items: buildBottomNavBarItems(),
),
);

So, I think. blue color container always on top in Widget tree.
But, blue container is not seen.
Also, it seems very weird, when I use flutter toast, the toast is always top in the widget tree and it visible.

So, How can it be?

Comienza con el punto de entrada WebviewScaffold y reproduce el problema usando el Stack y Positioned Container azul mostrado en el informe. Compara el orden de los widgets de Flutter con la forma en que el plugin presenta su capa nativa de WebView. Se considera terminado cuando se haya identificado la causa del Container que falta y se haya documentado o corregido el comportamiento esperado de apilamiento.

Escrito por el modelo de indexación a partir del texto del issue.