Reproducing the warning is pretty simple. In this case you can use the Qt example: "Simple Text Viewer" https://doc.qt.io/qt-6/qtassistant-simpletextviewer-example.html

Load the file into the text editor of the example application, highlight some text and try dragging it on a HighDPI display. The warning is logged onto the console:

PS:

The warning seems to come from:

QWindowsOleDropSource::createCursors()

I found another ticket related to this: https://bugreports.qt.io/browse/QTBUG-62787?focusedId=395296