With the release of Windows 10 version 2004, Microsoft has broken the ‘Fresh Start’ feature that allows you to perform a clean install of the operating system while retaining your data. Another option is Fresh Start, which will perform an almost clean install, but removes all applications, including those preinstalled by the manufacturer. Upon reset, it will reinstall any Microsoft Store apps that had been previously installed. With the standard method of launching Fresh Start being broken in Windows 10 2004, you need to use an elevated command prompt instead to launch the feature with Administrative privileges.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-2004-breaks-fresh-start-how-to-still-use-it/