I have two widget inside of one window. 
First widget is a program main menu. 
Second one open when user presses 'New project' button. 
I have enabled DPI via QT_SCREEN_SCALE_FACTORS + setAttribute(UseHighDpiPixmaps). 
I have icons dynamically scaled for second widget when I move app from one monitor (windows dpi 100%) to another monitor (windows dpi 175%). 
But first one (main menu) does not work this way.
It just preserves 2x icons without any respect to DPI. 
I found this by marking 2x icons. 
Also I was not able to reproduce this on the toy example. 
Could anyone please point me the right direction?