Webengine renders black page in multi-screen mode

I have a setup with multiple monitors driven by individual X11 screens.
On the first monitor QWebEngineView renders just fine. On other monitors the widget is pitch black.
When running in a mode with a single X11 screens and multiple randr displays things are fine.

I will attach a quickly hacked test app based on the manual qscreen test triggering the issue by showing a web page on all screens.