Xamarin.forms ios MonoTouchException on Navigation.RemovePage - xamarin

Question

In my xamarin.forms ios application I have 4 ContentPages and 1 Popup(Rg.Plugin)
My Navigation is like this
Page 1--> Page 2 --> Page 3 --> Page 4 --> Popup
I want to navigate to Page 1 from a button click in Popup by removing the pages(2,3,4 and Popup).
I done it like this.
private void OK_Clicked(object sender, EventArgs e)
{
try
{
var countPagesToRemove = 3;
var mainPage = (Application.Current.MainPage as NavigationPage);
for (var i = 1; i < countPagesToRemove; i++)
{
mainPage.Navigation.RemovePage(mainPage.Navigation.NavigationStack[mainPage.Navigation.NavigationStack.Count - 2]);
}
Navigation.PopAsync();
Task.Delay(5);
PopupNavigation.Instance.PopAsync();
}
catch (Exception ex)
{
DisplayAlert("Result", ex.Message, "ok");
}
}
This works perfectly on Android.In ios it throws me this exception.
Foundation.MonoTouchException
Message=Objective-C exception thrown. Name: CALayerInvalidGeometry Reason: CALayer bounds contains NaN: [0 0; 0 nan]
Native stack trace:
Source=Xamarin.iOS
StackTrace:
at ObjCRuntime.Runtime.ThrowNSException (System.IntPtr ns_exception) [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/13.14.1.39/src/Xamarin.iOS/ObjCRuntime/Runtime.cs:406
at ObjCRuntime.Runtime.throw_ns_exception (System.IntPtr exc) [0x00000] in /Users/builder/jenkins/workspace/xamarin-macios/xamarin-macios/runtime/Delegates.generated.cs:128
at (wrapper native-to-managed) ObjCRuntime.Runtime.throw_ns_exception(intptr)
at (wrapper managed-to-native) UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr)
at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Library/Frameworks/Xamarin.iOS.framework/Versions/13.14.1.39/src/Xamarin.iOS/UIKit/UIApplication.cs:86
at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0000e] in /Library/Frameworks/Xamarin.iOS.framework/Versions/13.14.1.39/src/Xamarin.iOS/UIKit/UIApplication.cs:65
I have no idea what does this mean. I have searched and many people got this issues in several situations.But I didn't something like my scenerio.How to solve this?Any help is appreciated.