MasterDetailPage - Secondary menu drawn twice on iOS

Hi,

my app uses Master-Detail navigation.
I push pages on the nav stack to have back button functionality.
When pushing a page with ToolbarItems (secondary menu), that's fine on Android, but it doubles the menu items on iOS.
Switching to the same page (not pushing), there is no problem on iOS (secondary menu shown once, as expected).

I adopted the official MasterDetail sample (https://github.com/xamarin/xamarin-forms-samples/tree/master/Navigation/MasterDetailPage) to show what I mean, see attached file:

Compile and start it on iOS device, press the button on the first page to open a sub page, and you should see doubled menu items (actually one which is drawn twice).
If you select the Reminder page through the Hamburger menu, the secondary menu is fine (even on iOS).

Some interesting parts:

ContactsPage.xaml.cs:
SwitchToDetailPageAndPushOnNavStack()

ReminderPage.xaml:

<ContentPage.ToolbarItems>
    <ToolbarItem Text="Do something" Clicked="OnDoSomethingClicked" Order="Secondary" />
</ContentPage.ToolbarItems>

Regards,
Heli