I just tried it again. I moved sheet1 to the last position.
In order to get the Project Explorer window to change, I had
to close the workbook and open it again. Now I have this listed.

Sheet1 (Sheet3)
Sheet2 (Sheet2)
Sheet3 (Sheet1)
ThisWorkbook

So, either the Project Explorer does not show the secret
code name of sheets  or it does and the advice given in
www.ozgrid.com/VBA/excel-vba-sheet-names.htm is wrong.