Microsoft released the KB4559004 non-security preview cumulative update with fixes for a File Explorer bug and an issue that caused Windows 10 computers with wireless wide area network (WWAN) LTE modems to lose Internet connectivity after installing the May KB4556799 update. Microsoft acknowledged this issue on May 22 saying that it affected both client (Windows 10, version 1909) and server (Windows Server) and Windows Server, version 1903) platforms. The issue was resolved today in the update that will be offered automatically to customers with the latest SSU through Windows Update.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-kb4559004-cumulative-update-fixes-file-explorer-lte-issues/