[REG 5.5->5.7] Windows: QGraphicsView draws artifacts around itself

QGraphicsView draws visual artifacts inside and even outside its borders, see attached picture for an example (both the top and the bottom widget are QGraphicsView).
Working well with Qt 5.5, reproduced with 5.7.0 and 5.8beta.
The artifacts disappear when using a QGLWidget viewport.

I don't have a code sample to reproduce it, but I can work on it if needed. If you want, you can use the code of my project :
https://github.com/wawanbreton/cvcomposer

Other information about what has been tested is on the forum :
https://forum.qt.io/topic/71459/qgraphicsview-drawing-artifacts