In Xamarin Forms 3.1, when using tabbed page with 4 tabs, how can I prevent "sliding" effect of tab bar on Android?

It looks like you are looking for this (not implemented yet) feature: [Enhancement] Implement fixed mode for Bottom Navigation Bar Android (Github)

I could solve it following this James Montemagno tutorial: Removing BottomNavigationView’s Icon Shifting in Xamarin.Android and implementing my own Tabbed Page custom renderer:

using Android.Content;
using Android.Support.Design.Internal;
using Android.Views;
using FixedTabbedPage.Droid.CustomRenderers;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;
using Xamarin.Forms.Platform.Android.AppCompat;

[assembly: ExportRenderer(typeof(TabbedPage), typeof(CustomTabbedPageRenderer))]
namespace FixedTabbedPage.Droid.CustomRenderers
    public class CustomTabbedPageRenderer : TabbedPageRenderer
        public CustomTabbedPageRenderer(Context context) : base(context) { }

        protected override void OnElementChanged(ElementChangedEventArgs<TabbedPage> e)

            if (ViewGroup != null && ViewGroup.ChildCount > 0)
                BottomNavigationMenuView bottomNavigationMenuView = FindChildOfType<BottomNavigationMenuView>(ViewGroup);

                if (bottomNavigationMenuView != null)
                    var shiftMode = bottomNavigationMenuView.Class.GetDeclaredField("mShiftingMode");

                    shiftMode.Accessible = true;
                    shiftMode.SetBoolean(bottomNavigationMenuView, false);
                    shiftMode.Accessible = false;

                    for (var i = 0; i < bottomNavigationMenuView.ChildCount; i++)
                        var item = bottomNavigationMenuView.GetChildAt(i) as BottomNavigationItemView;
                        if (item == null) continue;                         


                    if (bottomNavigationMenuView.ChildCount > 0) bottomNavigationMenuView.UpdateMenuView();

        private T FindChildOfType<T>(ViewGroup viewGroup) where T : Android.Views.View
            if (viewGroup == null || viewGroup.ChildCount == 0) return null;

            for (var i = 0; i < viewGroup.ChildCount; i++)
                var child = viewGroup.GetChildAt(i);

                var typedChild = child as T;
                if (typedChild != null) return typedChild;

                if (!(child is ViewGroup)) continue;

                var result = FindChildOfType<T>(child as ViewGroup);

                if (result != null) return result;

            return null;

You only have to add this code to your Android solution (refactoring namespaces) and here is the result:

Bottom Fixed TabbedPage on Android