When changing window state from Fullscreen to Maximized state, the window Minimizes first and then goes to Maximized state which offers a very poor user experience. I have seen that there where other issues in prior versions talking about this, for instance QTBUG-35166, but I still have the same issue in 5.11 on Windows 10. 

I have attached a little sample code which reproduces the issue, as it is a very light program the transition is really fast but you can see the effect. You simply need to toggle the option Fullscreen in one of the menus and then go back to Normal state. 

Also a screenvideo using my software:

http://recordit.co/1RMlDfKAU4

Thanks for your help!