I have built three Windows 2019 VMs and none of them are joining the WSUS server.
I have done the following troubleshooting to no avail:
Verified the servers are in the correct IP network.
Verified the servers are in the correct AD group.
Verified that the servers are part of the correct GPO and that the WSUS group policy is enabled and enforced.
Verified that the servers can reach these two links:
http://server.domain.local:8530/selfupdate/iuident.cab
http://server.domain.local:8530/ClientWebService/client.asmx
Verified that the servers can ping the WSUS servers via their domain name.
Verified that IPv6 is not enabled. It is not enabled on any of our servers.
Solarwinds is not monitoring these servers yet.
Verified that the registry key KEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate\AU\UseWUServer is set to 1.
Verified that the servers are trying to get updates from the WSUS.
No SCCM in the system.
Server Cleanup Wizard ran successfully last week.
What could be causing these not to show up?