Fix for Xamarin Forms Shell UseSafeAreaInsets Bug

ContentPageRender.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using CommonAlly.iOS.Controls;
using Foundation;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

[assembly: ExportRenderer(typeof(ContentPage), typeof(ContentPageRenderer))]
namespace CommonAlly.iOS.Controls
{
    public class ContentPageRenderer: Xamarin.Forms.Platform.iOS.PageRenderer
    {
        Page Page => Element as Page;
        public override void ViewDidLayoutSubviews()
        {
            base.ViewDidLayoutSubviews();

            UpdateShellInsetPadding();
        }

        public override void ViewSafeAreaInsetsDidChange()
        {
            base.ViewSafeAreaInsetsDidChange();

            UpdateShellInsetPadding();
        }

        private void UpdateShellInsetPadding()
        {
            if (Page != null)
            {            
                var bottom = 0d;

                if (Element?.Parent?.Parent is Tab)
                {
                    bottom = Page.Padding.Bottom;
                }
            
                Page.Padding = new Thickness(
                    Page.Padding.Left,
                    0,
                    Page.Padding.Right,
                    Page.Padding.Bottom
                );
            }
        }
    }
}

Great! You save my time....