Microsoft says some users might experience OneDrive connectivity issues after updating their devices to Windows 10, version 2004 or enabling Files on Demand in OneDrive. Affected devices might not be able to download new Files On-Demand or open previously synced/downloaded files. Microsoft is currently investigating this issue and is working on a fix that will be provided to all affected users in an upcoming update. Microsoft initially recommended rolling back the May 2020 Update (version 2004) until a resolution for this issue is available.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-2004-breaks-onedrive-connectivity-for-some-users/