Microsoft has released a new optional preview update that fixes two bugs that prevent Windows 10 2004 users from connecting to the Internet. Windows 10 users saw ‘No Internet’ message in the Network Connectivity Status Indicator (NCSI), even though their Internet worked fine. Users with WWAN LTE modems could not connect to the internet, even if the NCSI status showed that they were connected. Microsoft placed a compatibility hold on Windows 10 upgrades for devices with these modems. The compatibility hold has been removed, and affected users can not upgrade to Windows 10.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-fixes-windows-10-internet-connection-issues-in-new-update/