Crash or Memory leak of QSGGeometry Class

I have wrote my own QQuickItem and overriding the QSGNode * updatePaintNode(QSGNode *, UpdatePaintNodeData *) method to show own geometry.
The Item is updated every 15ms with a Timer and embedded in a Swipeview. When I often switch the tabs, the memory consumption of the whole application keeps growing and after some time the whole UI will start flickering. The Problem exists only on Windows 7.
When I call the method QSGGeometry::allocate(int,int) with a big value(eg. 10'000'000), the application will crash ( only when i use the Material design ) Message in console: Invalid parameter passed to C runtime function.
Compiler MinGW. Testet with QT 5.9 - 5.11.
Until now I was unfortunately not able to build an application that only contains the Problem.