The Layout coordinator makes the anchored item disappear when scrolling up

Question

I have a really uncomfortable problem that I cannot get rid of and that I absolutely do not understand.

I just want my app bar to crash and the image to move with some placeholder in the app bar area. I got this from this example: https://github.com/saulmm/CoordinatorBehaviorExample

I use a very simple layout:

<CoordinatorLayout>

    <AppBarLayout>
        <CollapsingToolbarLayout
            android:minHeight="96dp"
            app:layout_scrollFlags="exitUntilCollapsed|scroll">
            <FrameLayout android:id="@+id/anchorPlaceHolder .../>
        </CollapsingToolbarLayout>
    </AppBarLayout>

    <NestedScrollView ...>

    <ImageView
        app:layout_anchor="@id/anchorPlaceHolder
        ...
        />

</CoordinatorLayout>

Everything works as expected - EXCEPT one massive error. When the scroll reaches its upper end - otherwise the toolbar reaches its minimum height - my image just disappears. It is "off" - and I do not know why and who does it.

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Answer 1

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