Excel thumbnails in Taskbar are gray and dull
In the taskbar of Windows 10 I can see the thumbnails of all the open workbboks of an Excel application.
(I believe thumbnail is the correct term).
Sometimes these are show pretty dull, i.e. sometimes they are just gray boxes without any information (and even hovering shows the temporary full preview window just as dull).
Sometimes these shows any the filename (or actually the windows caption I guess).
Sometimes they are properly filled with info.
It is bit difficult to make an exact repro, but using C# console app and opening a bunch of excel files shows some problems if the workbooks are opened and then immediately minimized (window state of all (normally only 1) the workbook windows).
However if I delay the minimizing a few hundred milliseconds after opening, they seem to be ok.
Anyone may shed some light on this problem?