QMessageBox does not scale well when using per monitor dpiawareness mode

While using QMessageBox with a per monitor dpi awareness mode enabled, when moving the messagebox from highdpi (200% scaled) monitor to a low dpi (100%) monitor, the contained icon and text are not scaled up. The messagebox size, buttons and title are properly scaled up.

As a reference, QMessageBox::aboutQt() does scale properly.

Steps to reproduce:

• Have a high dpi (4k) primary monitor with 200% scaling set
• Have a secondary low dpi monitor with no scaling (100%)
• Run attached sample, so that it starts in the primary high dpi monitor
• Move message box to secondary low dpi monitor
• EXPECTED: Message box is properly scaled up
• ACTUAL: The icon and text of the message box are not scaled