Reset Remote Desktop service configuration
The "Reset Remote Desktop service configuration" function should include resetting the (possibly modified) RDP port number to 3389 in the registry.
The registry key is HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\TerminalServer\WinStations\RDP-Tcp\PortNumber
This may be a non-typical cause for inability to get into RDP contact with the VM, but when it is the problem then resetting the port number would be a life-saver. It would have saved me quite a few hours and the expenditure of a support incident.