QEntities are displayed depending on the order of their instantiation

The bug occurs during runtime:
3D objects (e.g. Spheres, Cylinders) are not displayed correctly according to their spatial positioning/depth in a 3D scene. The order of instantiation determines how objects cover each other.
In other words: the firstly created QEntity is in the absolute background and the lastly created QEntity is always in the foreground. This happens regardless of where the QEntities are positioned and how the camera is rotated.

The bug was found by two users (Finn, Ian Bray) in different system environments (MacOS Sierra, Ubuntu 16.04, Windows 10) with Qt 5.7.0. and is discussed in detail in the following forum entry:
https://forum.qt.io/topic/74419/a-weird-bug-why-is-there-no-spatial-depth-in-my-3d-scene/16

The user kshegunov (using version Qt 5.7.2 ) could not reproduce the bug.

A project folder of a minimum working example (compiled with brew install Qt5 in CLion on MacOS Sierra) and screenshots of the correct and incorrect result are provided in the Archive.zip file.