ConstraintLayout Barrier not visible in design view

问题

I'm trying to add a barrier to my ConstraintLayout in Android Studio but it is not showing up the way it should in design view.

I have been following this tutorial, but I can't get things to work properly.

I'm currently using:

Android Studio 3.1.1
androidx.constraintlayout:constraintlayout:1.1.3

Things I have tried:

Invalidate caches/restart
Removing the attribute tools:layout_editor_absoluteX
Fiddling around!

Here's my test.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">

    <Button
            android:text="Button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/button" android:layout_marginTop="8dp"
            app:layout_constraintTop_toTopOf="parent" app:layout_constraintStart_toStartOf="parent"
            android:layout_marginStart="8dp"/>
    <Button
            android:text="Button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/button2" android:layout_marginTop="8dp"
            app:layout_constraintTop_toBottomOf="@+id/button" app:layout_constraintStart_toStartOf="parent"
            android:layout_marginStart="8dp"/>
    <androidx.constraintlayout.widget.Barrier android:layout_width="wrap_content" android:layout_height="wrap_content"
                                              android:id="@+id/barrier2" app:barrierDirection="end"
                                              app:constraint_referenced_ids="button,button2"
                                              tools:layout_editor_absoluteX="411dp"/>
</androidx.constraintlayout.widget.ConstraintLayout>

In design view, it looks like this

The barrier is stuck to the edge of the layout and doesn't move no matter what I do. If I set barrierDirection start or left it is not visible at all. If I set end or right the dashed line shows up but is stuck to the left side of the layout.

Barriers seem to work fine in another project started from scratch, but this uses the android.support.constraint.ConstraintLayout rather than the androidx library's.