MDI Area Ghosting

[Griffy]

Hi All,

I am returing to QT (PySide6) after a few years doing other things...

I am trying to set up an app with an MdiArea. I am creating a new test window, but when I move it around I see this horrible "ghosting" effect.

Interestingly, I also see this in the QtDesigner:

Any ideas what's causing this and how to fix it?

Thank you,

Griffy