Its already wild enough that AutoCAD and Excel are both broken partially in Win11 because MS changed something in classic Paint that effects how Windows 11 does image embedding.
From AutoCAD's known issues page: On the Windows 11 operating system, OLE image objects (BMP, PNG, GIF, and so on) don’t display and can’t be plotted as expected. This is due to a limitation in the Paint application that ships with Windows 11. AutoCAD LT is affected the same way other Windows applications are affected.
From AutoCAD's known issues page: On the Windows 11 operating system, OLE image objects (BMP, PNG, GIF, and so on) don’t display and can’t be plotted as expected. This is due to a limitation in the Paint application that ships with Windows 11. AutoCAD LT is affected the same way other Windows applications are affected.