rendering bug

When we are displaying a slice of IVUS image using vtkImageViewer2, a zoomed image of the bottem-left corner of the renderwindow will somehow be displayed at the top-right quarter of the window.

If we rotate the Camera by some angle, the zoomed image still exist.

Only when slice<10 and the method SetSlice(slice) is called, this bug can occour.
And after any events triggering rendering happened the zoomed image would disappear.
Everything was fine before we upgrade vtk 8.0.1 and qt5 to vtk 9.2.6 and qt6, and replacing QVTKWidget2 by QVTKOpenGLNativeWidget.

Any ideas?