SetFitsSystemWindow programmatically doesn't work as expected

Question

I'm trying to work with different AppBarLayouts in one Activity.
When a Fragment is loaded, it can call a "ToolbarManager", that handles the replacing of the currently active Toolbar (namely an AppBarLayout). For some of these Toolbars (using CollapsingToolbarLayout) I want them to draw behind the StatusBar.
This works fine when setting the "fitsSystemWindow" to true in the XML. But when using just a Toolbar with layout_scrollFlags="scroll", the Toolbar Title is displayed even behind the StatusBar.

To avoid this, I want to disable the "fitsSystemWindow" when loading such a Toolbar by using setFitsSystemWindow(false).

Disabling works fine, but when re-enabling by setFitsSystemWindow(true) for using with CollapsingToolbarLayout, the StatusBar is colored and the Toolbar is placed below the StatusBar with a padding in size of the StatusBar on top.

Image: Drawn below StatusBar instead of behind

When I don't use setFitsSystemWindow(true) and just set it to true in the XML layout, the display of CollapsingToolbarLayout is fine.

Is this a bug in setFitSystemWindow or is this method just different from the XML attribute?

Here are the layouts I use:

Activity:

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/drawer_layout"
    android:fitsSystemWindows="true"
    tools:context=".activities.MainActivity"
    style="@style/AppTheme">

<android.support.design.widget.CoordinatorLayout
    android:layout_height="wrap_content"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:fitsSystemWindows="true"
    android:id="@+id/coordinator_layout">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:fitsSystemWindows="true"
        android:layout_height="wrap_content">

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


    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/fragment_container"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

    </FrameLayout>

    <ProgressBar
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:indeterminate="true"
        android:indeterminateDuration="1000"
        android:layout_marginBottom="-7dp"
        android:id="@+id/loadingBar"
        style="@style/Widget.AppCompat.ProgressBar.Horizontal"
        android:layout_gravity="center_horizontal|bottom"
        android:gravity="bottom"/>
</android.support.design.widget.CoordinatorLayout>

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

The AppBarLayout is replaced every time a new Fragment is loaded.

The following layout is the Toolbar which should not draw behind the StatusBar, but the Toolbar should scroll (leaving only the TabLayout visible)

<android.support.design.widget.AppBarLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
    android:id="@+id/toolbar_discover"
    android:fitsSystemWindows="true"
    android:paddingBottom="0dp">

    <android.support.v7.widget.Toolbar
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:id="@+id/toolbar"
        android:layout_height="?attr/actionBarSize"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:theme="@style/AppTheme.Toolbar"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
        app:layout_scrollFlags="scroll|snap">

    </android.support.v7.widget.Toolbar>

        <android.support.design.widget.TabLayout
            android:id="@+id/tablayout_discover"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom"
            app:tabMode="fixed"
            app:tabGravity="fill" />
</android.support.design.widget.AppBarLayout>

This used to work when I set fitsSystemWindows=false on the CoordinatorLayout in the MainActivity Layout. When doing so, the following CollapsingToolbar cannot draw behind the StatusBar.

<android.support.design.widget.AppBarLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
    android:id="@+id/toolbar_account"
    android:fitsSystemWindows="true"
    android:paddingBottom="0dp">

    <android.support.design.widget.CollapsingToolbarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"
        app:contentScrim="?attr/colorPrimary"
        android:fitsSystemWindows="true"
        android:id="@+id/collapsingToolbarLayout">

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="250dp"
            android:scaleType="centerCrop"
            android:fitsSystemWindows="true"
            app:layout_collapseMode="parallax"
            android:id="@+id/banner_image"
            android:src="@mipmap/img_header"/>

        <android.support.v7.widget.Toolbar
            xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="match_parent"
            android:id="@+id/toolbar"
            android:fitsSystemWindows="false"
            android:layout_height="?attr/actionBarSize"
            xmlns:app="http://schemas.android.com/apk/res-auto"
            android:theme="@style/AppTheme.Toolbar"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            app:layout_collapseMode="pin">

        </android.support.v7.widget.Toolbar>
    </android.support.design.widget.CollapsingToolbarLayout>

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