QWebEngineView and high DPI scaling cause rendering issues on Mac

 
QWebEngineView causes major rendering issues on Mac when used with high DPI scaling enabled.

After launching the app it looks like only a part of the window is occupied by controls and the rest of it is blank (see the image above).

Once resized, it occupies the whole window area, but everything becomes blurry (see the image below):

A small sample project to reproduce the issue has been attached.