Microsoft has update the document for "Remote Desktop IP Virtualization in Windows Server 2019" in Nov 2021.
https://docs.microsoft.com/en-us/troubleshoot/windows-server/remote/remote-desktop-ip-virtualization
I have tried but it doesn't work. My testing lab has a Windows 2016 also, and it works without any problem.
The windows server 2019 is fresh install by using of evaluation iso.
DHCP is properly config. When second user logon the Windows 2019, no additoanl IP is displayed by using of "ipconfig /all" command
Is there anyone success?