When occt 7.6 is used with Qt viewer windows has misalignment with windows. Or the mouse pointer and marker locations are different. It does not happen with Qt 5.15.2
Attached is the screen of the sample occt viewer. (Location of mouse pointer is different from market on screen). I also compiled Mayo viewer (https://github.com/fougue/mayo.git) with Qt6.3 and Occt 7.6. The viewport size is smaller than windows which did not happen with Qt 5.15.2.
How can it be corrected?