I created my project in full hd (1920x1080) and I want to run the application in full hd and in 4k (3840x2160), when it’s been executed it in 4k only the windows are resized but the popups are of the same size as in full hd. In one occasion was resized well for a moment without modifying the designer.
Get the monitor's resolution, then resize your popups accordingly...