https://www.bleepingcomputer.com/news/microsoft/microsoft-removed-another-windows-10-2004-safeguard-hold/ > Microsoft removed a Windows 10, version 2004 compatibility hold blocking devices with certain WWAN LTE modems from upgrading to the latest Windows version. > Safeguard holds (also known as compatibility holds) are added by Microsoft based on known issues and diagnostic data to delay Windows upgrades on affected devices and to protect the end-users' smooth experience.