Application crush in ~QApplication() on QFontCache clearing, when used QStringLitheral for font family name in dynamic library

Application crush in ~QApplication() on QFontCache clearing, when used QStringLitheral for font family name in dynamic library.
Steps :
1. Create widget with changed font family in dll( "Changed font" button in this example )
2. Destroy widget
3. Unload dll
4. Destroy QApplication
Button "Default font" calls create widget with default font family. No crash.

I often load / unload plugins for my application in work mode and I need unload all plugins before destroying of QApplication.
If widget created via QtDesigner uic.exe wrap font family name by QStringLiteral, then application will crush.
If I manually install font family without QStringLiteral, the application will finish correctly.