I'd still be interested to know if your ProSeries is installed under "C:\ProWin20" or a different folder. Especially if it's installed in a folder with blank spaces in it. Like for example "C:\Pro Series\ProSeries2020" or "C:\ProSeries\Professional 2020".

By the way, you can always go the other way, import QuickBooks data into the ProSeries tax return. Open the tax return in ProSeries and go to the menu "Import->Update Return with QuickBooks Data..."