This is a continuation of
QTBUG-97533 which was closed in October.
I'm a QT licensee. One of my customers has reported this problem on a three monitor PC, for an app built with Qt 6.2.4. See attached photo IMG_2807.JPG.
(The same app built with QT 5.15.5 works correctly.)
One possible clue in addition to
QTBUG-97533. My customer is running 2 monitors on internal graphics and 1 monitor on a USB-3 display interface. Maybe when multiple video cards are in use, Qt6 is loosing track of where to put things?
I have asked the customer to disconnect the USB-3 interface and test again.