Weird QComboBox behaviour under Qt 5.5.1 linuxfb platform (Yocto build for imx6UL)

[sanityConf]

I am getting weird behaviour of QComboBox when using Qt 5.5.1 linuxfb platform on an embedded linux Freescale imx6ul board. I am using a Yocto build for the embedded distribution.
I need to rotate my application by 90 degrees on the screen, so I use QGraphicsScene and QGraphicsView.
This is a solution I have found online.
Relevant code:

QGraphicsScene *scene = new QGraphicsScene();
QGraphicsView *view = new QGraphicsView(parent);
view->setGeometry(0,0,800,480); // actual Display size
view->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
view->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

view->setAlignment(Qt::AlignHCenter);
scene->setBackgroundBrush(Qt::blue);
scene->setItemIndexMethod(QGraphicsScene::NoIndex);

QGraphicsProxyWidget *proxy = scene->addWidget(this);
view->setScene(scene);
view->show();
view->rotate(90);

But then when I press on the QComboBox, the list of items gets displayed in the wrong position.
When I compile the exactly same code for Qt 5.6 on Ubuntu 14.04 desktop, I do not have this weird behaviour.

I attach the relevant part of a screenshot to illustrate the problem.

Any useful comments and solutions would be greatly appreciated.
Also, if you know a better alternative way of how to rotate an entire Qt5 Qt Widget application on linuxfb platform, that would also be of great use.

Link to screenshot:
http://h.dropcanvas.com/1atuf/screen2_edited_2.png

[A Former User]

Hi, welcome to the Qt forum! Please file a bug report: https://bugreports.qt.io