Botão FAB não move

Sempre que movo o botão FAB utilizando a visão de design ele entra no ListView e gera um erro no xml.

Assim está o código assim que adiciono o FAB:

<?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">

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/floatingActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="true"
        app:srcCompat="@android:drawable/ic_menu_add" >
    </com.google.android.material.floatingactionbutton.FloatingActionButton>

    <ListView
        android:id="@+id/activity_main_lista_de_alunos"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </ListView>


</RelativeLayout>

E quando movo ele usando o design ele fica assim:

<?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">

<ListView
    android:id="@+id/activity_main_lista_de_alunos"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/floatingActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="true"
        app:srcCompat="@android:drawable/ic_menu_add"></com.google.android.material.floatingactionbutton.FloatingActionButton>
</ListView>


</RelativeLayout>