I have the same problem but I do not have AD. On the Windows server 2016 version, it worked correctly with the same licenses.
Could the reason be the fact that earlier the server had a different naming than today. So I wonder if the license seems to be a different server so they do not want to cooperate?
In addition, this RDS server 2019 is a virtual machine on HyperV whether it changes anything.
after I got the time limits and it still doesn't work,
Please help.