hide QQuickWindow on Ubutun 18.04LTS with NVIDIA proprietary driver would cause crash

hi, I'm making an whiteboard application with qt5.9 for linux desktop, and there are issue I encounter:

when I try to hide a window that inherit by QQuickWindow, I get a crash on Ubutun 18.04LTS with NVIDIA proprietary driver, which is my develop devices.

then I change my window class inherit to QWindow or change my display driver to  nouveau drivers for NVIDIA, problem vanish. so there must be some happen about this, and I need Qt engineer help me to fix this.

there are a demo base on qt example rasterwindow would show this: once you double click the first show window, the second window shows up, and then double click the first show window again, you can get the crash if you use the NVIDIA proprietary driver.