Widgets and fonts have wrong size after moving to screen due to disconnect with different DPI when dpiawareness = 2

I have a laptop with 15" 4k screen (pixel ratio is 3) and external Full HD 23" display (pixel ratio is 1). I configured the Display Settings of the OS to use only external display when it is connected and to use 250% scaling for the 4k display.

So, if I launch an application and then connect or disconnect the external display, all applications get moved to a screen with different DPI. This results in wrong sizes for some widgets in fonts. I see from logs, that application uses dpiawareness = 2 which is default.

I compiled the Validator example from the Qt distribution. I attached screenshots for application started at low DPI and at high DPI screen and what application looks like after move to high and low DPI screen (by connecting/disconnecting the external display).

 Steps to reproduce:

• Connect HIgh DPI Monitor to Laptop
• In display settings, toggle Mode from "Show only on1"/"Show only on2"