This issue occurs because of using the xsetup.exe. Can you try using the xsetup.bat which should be available under bin/ directory. For Windows Installations, this should work fine.
Also, if the requirement is to have an updated Vitis installation, I would not recommend updating 2020.1 because Vitis doesn't have any updates in the 2020.1.1 release. So you can save time and space there. 2020.1.1 is meant only for Vivado related updates. But if you plan to use Vivado too, then please feel free to update the tool.