flutter navigator 2.0 on ios - ios

Question

i'm creating a Flutter native App implementing navigator 2.0
everything works fine in android simulators, even built and deployed to internal tests in play store.
now i started trying on IOS ( didn't have access to ios emulator before )
after many struggles i get the app working ... but i still have an issue
on navigation delegate
i have a pagelist on which i append various screens depending of the state.
everything works fine for 3 different screens.(the 3 most complicated)
and i always have at most 2 screens built
but when i add the last one, which is an onboarding screen for the first launch of the app with liquid swipe i have the following error when i touch the screen.
════════ Exception caught by gesture library ═══════════════════════════════════
The following assertion was thrown while routing a pointer event:
RenderBox was not laid out: RenderUiKitView#a395b NEEDS-LAYOUT NEEDS-PAINT
'package:flutter/src/rendering/box.dart':
package:flutter/…/rendering/box.dart:1
Failed assertion: line 2001 pos 12: 'hasSize'
════════ Exception caught by services library ══════════════════════════════════
A KeyUpEvent is dispatched, but the state shows that the physical key is not pressed. If this occurs in real application, please report this bug to Flutter. If this occurs in unit tests, please ensure that simulated events follow Flutter's event model as documented in `HardwareKeyboard`. This was the event: KeyUpEvent#2b4f8(physicalKey: PhysicalKeyboardKey#700e3(usbHidUsage: "0x000700e3", debugName: "Meta Left"), logicalKey: LogicalKeyboardKey#00106(keyId: "0x200000106", keyLabel: "Meta Left", debugName: "Meta Left"), character: null, timeStamp: 283:31:49.450445)
'package:flutter/src/services/hardware_keyboard.dart':
package:flutter/…/services/hardware_keyboard.dart:1
Failed assertion: line 432 pos 16: '_pressedKeys.containsKey(event.physicalKey)'
for debuging, i removed the onboardingscreen and added a simple
if (_searchScreen) {
pageList.add(CupertinoPage(
child: SearchScreen(
searchViewModel: SearchViewModel(_apiInstance, DbInstance(), this,
words: _words),
)));
}
if (_displayOnboarding) {
pageList.add(MaterialPage(
child: Scaffold(
appBar: AppBar(),
body: Container(child: Text('test')),
)));
}
it builds and renders screen but when i touch the screen i get the same errors as before
do you have any idea of what's the issue??
thank you!