As the two most stable versions of windows 10 system, version 1903 / 1909 also appeared after the update, which has been confirmed by Microsoft.
Microsoft quietly updated the Windows 10Version 1903/1909 feature update support document, in
Specifically, when any Windows 10Version 1903/1909 previous versions upgrade to these two features, you may receive a top-level update
You may receive this compatibility warning when LOCAL SYSTEM accounts are blocked from accessing the Internet via HTTP in the firewall. this is due to Windows 10 setting dynamic update (DU) can not download the required package.
The current solution is that you can enable HTTP access for windows 10 settings dynamic update (DU) when using a local system account, but a better solution Microsoft is still working on and says it will provide updates in the upcoming release.