QtQuickControls 2 Fusion style broken on current Gnome

QtQuickControls 2 Fusion style is unusable on current Gnome. I tested the following on the current Fedora Rawhide with its default Gnome desktop and Qt packages (Gnome 3.33, Qt 5.12.4).

The attached screenshot shows the Slider item from the gallery example in the qt5-qtquickcontrols2-examples package after switching the style to Fusion. As can be seen, only the knob of the sliders are visible, but not its sliding line. Other problems I noticed are: the menus borders are invisible (black menu background on black window background) and so are menu items that are not enabled (black text on black background).