Server 2019 Hyper-V Guest Remote Desktop Connection Unstable

ARMITGuy4839 

We are experiencing similar issues.

Specifically

Host must be 2019 1809 (fully patched), Guest must be 2019 1809 (fully patched).  RDP connection from the same network segment is OK.

If we come from another network (across WAN or VPN), then RDP sticks at "Securing Remote Connection".

Interestingly, on the guest, if logged in locally on the console, you will be locked out when RDP commences. (i.e. RDP session is starting).

If we use an invalid user, or user without permission, we get the expected error. (so authentication and permission evaluation is working).

If we run a 2016 guest on the same host, it's fine.

If we move the 2019 guest to a 2016 host in the same VLAN and physical switch, it's fine.

Wireshark shows the bidirectional conversation happening, but no clue to why it's failing.

Nothing in event log either side.  We've turned off Windows firewall for testing. 

Other network services are fine, for example, SMB.  So file shares on the guest are fine. It's specifically RDP, on a 2019 guest, on a 2019 host, when coming from a different network.

We've escalated to Microsoft using up some Software Assurance benefits.  Never had to do this before, but it's got us flummoxed.  We've had our best networking consultant on it, and he has no idea either. It does seem to be Windows itself with the issue, as we've proven the fundamental networking is OK.

My gut feel, is it's a software bug in the VSwitch.  So a fix may be far away.