MDI subwindows leave artifacts when moving/resizing with fractional scaling

Tested Qt 6.2.3 (as released) and the dev branch from 1/31/2022. When moving a subwindow in an MDI area, there are artifacts left behind, until something triggers updating the affected areas eventually.

This is not happening with the scale factor set to 100% or 150%, but happens consistently with 125%.

Applying the work in progress patch https://codereview.qt-project.org/c/qt/qtbase/+/392989 reduces the size of the artifacts somewhat but there are still thin lines left behind.

Pictured below is the widgets/mainwindow/mdi example: