Flutter: Cant position a container over another using offset - animation

Question

So I have written this code which lets an animation play where i pressed. So if i press the screen there is a short animation playing where i pressed, if you press multiple times there are multiple animations on the screen for a short period. Each time I press the screen there is a container taking up place where the animation is played, but I cant stack a container over another, So if i press on the screen where there already is a container an animation won't be played. It seems that Positioned wont work if i press where there already is a container. How do I stack a container over another so that I can press on the same place and play multiple animation over another?
This is all the code responsible for that animation:
class HomePage extends StatefulWidget{
#override
_HomePageState createState() => _HomePageState();
}
class _HomePageState extends State<HomePage>
with SingleTickerProviderStateMixin {
final tappedPositions = <Offset>[];
AnimationController _animationController;
#override
void initState() {
_animationController = AnimationController(
vsync: this,
duration: const Duration(seconds: 2),
);
super.initState();
}
#override
Widget build(BuildContext context) {
return new Stack(
children: <Widget>[
new Column(
children: <Widget>[
new Expanded(
child: Container(
color: Colors.blue,
))]),
new GestureDetector(
onTapDown: (tabDetails) {
setState(() {
tappedPositions.add(tabDetails.localPosition);
Future.delayed(const Duration(seconds: 1), () {
tappedPositions.removeLast();
});
});
},
child: Stack(
children: <Widget>[
Container(
height: 370,
color: Colors.transparent
),
])
),
for (final position in tappedPositions)
Positioned(
top: position.dy-50,
left: position.dx-50,
child: MyAnimatedWidget(
animation: _animationController,
))]);
}
}
class MyAnimatedWidget extends StatelessWidget {
final Animation animation;
const MyAnimatedWidget({Key key, this.animation}) : super(key: key);
#override
Widget build(BuildContext context) {
return AnimatedBuilder(
animation: animation,
child: Stack(
children: <Widget>[
Container(
height: 100.0,
width: 100.0,
color: Colors.red
/* new FlareActor(
"assets/images/tryck2.flr",
animation:"tryck",*/
),
],
),
builder: (context, child) {
return Stack(
children: <Widget>[
new Container(alignment: Alignment.center,
child: child,)
],
);
},
);
}
}
PS (I have already asked this question and tried to make it work but have not succeeded, therefore I am asking again, I'm new to dart and programing in general)