弹出窗口时，AppBar会滚动

Question

我PopupMenu中有Fragment。

   PopupMenu popupMenu = new PopupMenu(getContext(), v, Gravity.END);

我的AppBarLayout在滚动时退出了屏幕内容。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

    <android.support.design.widget.CoordinatorLayout
        android:id="@+id/coordinator"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <android.support.design.widget.AppBarLayout
            android:id="@+id/app_bar_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/MyMaterialTheme.AppBarOverlay">

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="?attr/colorPrimary"
                app:layout_scrollFlags="scroll|enterAlways"
                app:popupTheme="@style/MyMaterialTheme.PopupOverlay" />

            <android.support.design.widget.TabLayout
                android:id="@+id/tab_layout"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:layout_scrollFlags="scroll|enterAlways"
                app:tabIndicatorColor="@color/colorWhite" />

        </android.support.design.widget.AppBarLayout>

        <android.support.v4.widget.NestedScrollView
            android:id="@+id/nest_scrollview"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior">

            <android.support.v4.view.ViewPager
                android:id="@+id/view_pager"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_below="@id/tab_layout">
            </android.support.v4.view.ViewPager>
        </android.support.v4.widget.NestedScrollView>

    </android.support.design.widget.CoordinatorLayout>

</RelativeLayout>

在 Android 5 上，它可以正常运行，但 Android 4.1 AppBarLayout在Popup出现时滚动