[Reg 6.6.3 -> 6.7.0] Graphical glitch in QMdiSubWindow

We upgraded from Qt v6.6.3 to v6.7.3 with no other source changes in our application.  While v6.6.3 worked correctly, we have observed a graphical glitch in v6.7.3 and later.  We are creating a main MDI area using QMdiArea, and then adding subwindows as QMdiSubWindow.   When this is done, each subwindow has a graphical glitch that represents itself with another apparent status bar at the bottom of the QMdiSubWindow, although what is shown in the status bar area is a mirror of whatever graphics are below the QMdiSubWindow (normally from different widgets entirely).  While this appears to be a graphical glitch, it does actually affect the QMdiSubWindow coordinates so it must think that there is actually another widget at the bottom of each QMdiSubWindow.  What makes this issue even more mysterious is that when subwindows are created on the primary monitor the status bar behavior occurs, but when subwindows are created on an extended monitor the behavior never occurs.  I have attached a video demonstrating the behavior on a primary monitor.