UnifiedTitleAndToolBarOnMac glitch when QGLWidget is used
A couple of months ago I reported this bug to the Qt team: https://bugreports.qt-project.org/browse/QTBUG-39781
I have tried to found a workaround without much luck.
I have added a QQuickView to my project for using a QML based component. It is using OpenGL for the rendering and the bug is not present, so I think that the bug could be related with the QGLFormat configuration.