QWebEngineView breaks when not set as a central widget

When a QWebEngineView is set as a child widget to another widget (ex. in a tab of a QTabWidget), and two QWebEnginePages are swapped between, the view instead of showing the correct page, shows its parent widget (as shown in the attached image). The console has the following message outputted many times:

QOpenGLWidget cannot be used as a native child widget. Consider setting Qt::AA_DontCreateNativeWidgetAncestors and Siblings.

This doesn't happen if the view is set as centralWidget.

I've attached a sample code of the bug. To replicate, press 'Show page A', then 'Show page B', and then 'Show page A' again. On my system, it produces the result show in the snapshot.

I have attempted to recreate the problem on other machines running both ArchLinux and Windows 7, but have been unable to. The only major difference is that on my hardware I have both an integrated graphics card and a mobile graphics card (nvidia gt540m, running latest proprietary drivers), whereas both other machines have regular nvidia graphics cards.