折叠工具栏布局不能平滑滚动

Question

我正在使用下一个代码制作一个显示图像的collpasing工具栏，然后在用户向下滚动时折叠工具栏：

<?xml version="1.0" encoding="utf-8"?>

<android.support.design.widget.AppBarLayout
    android:id="@+id/app_bar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:fitsSystemWindows="true"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar"
        android:layout_width="match_parent"
        android:layout_height="240dp"
        android:fitsSystemWindows="true"
        app:contentScrim="@color/colorPrimary"
        app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed">

        <ImageView
            android:id="@+id/iv_cover"
            app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scaleType="centerCrop"
            app:layout_collapseMode="parallax"
            android:contentDescription="@string/app_name"/>

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_collapseMode="pin"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
            app:titleTextAppearance="@style/Toolbar.TitleText"
            app:subtitleTextAppearance="@style/Toolbar.SubtitleText" />

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

<include layout="@layout/content_commerce" />

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_margin="@dimen/fab_margin"
    android:src="@drawable/ic_promotions_white_24dp"
    app:layout_anchor="@id/app_bar"
    app:layout_anchorGravity="bottom|end" />

问题是折叠工具栏无法顺畅滚动。当工具栏完全折叠时，其余的布局滚动得很好，但如果工具栏没有完全折叠，则滚动运动不自然。 “content_commerce.xml”布局是这样的：

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/colorWhite"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <!--Presentation-->
        <include
            layout="@layout/content_commerce_presentation"/>

        <!--Description-->
        <include
            layout="@layout/content_commerce_description"/>

        <!--Entrys - categories-->
        <include
            layout="@layout/content_commerce_entries_categories"/>

        <!--Payment Methods-->
        <include
            layout="@layout/content_commerce_payment_methods"/>

        <!--Additional Information-->
        <include
            layout="@layout/content_commerce_additional_information"/>

        <!--Contact Information-->
        <include
            layout="@layout/content_commerce_contact"/>

    </LinearLayout>

</LinearLayout>

其余布局不包含任何可滚动视图，只包含LinearLayouts，TextViews和ImageViews。