virtualbox support vnc rather than rdp connections even after virtualbox-ext-pack is installed

The rdp connection support supposed to be installed with virtualbox-ext-pack does not work. Logging into the rdp port with telnet shows the message:

"RFB 003.008"

This indicates a RFB/VNC style display server rather than the RDP server in the extension pack. This may be occurring because there is or was code in the source package enabling an RFB server, so that the extension pack would not be required for remote display capability.

I wouldn't mind using the RFB display server if it were documented, but I haven't found any documentation for how to connect to it successfully with e.g. VNC or Remmina. In any case, I expect most folks installing the extension pack are expecting to get a function RDP server.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: virtualbox 6.1.2-dfsg-1
ProcVersionSignature: Ubuntu 5.4.0-12.15-lowlatency 5.4.8
Uname: Linux 5.4.0-12-lowlatency x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu16
Architecture: amd64
CurrentDesktop: KDE
Date: Wed Feb 5 15:11:29 2020
InstallationDate: Installed on 2020-01-23 (12 days ago)
InstallationMedia: Kubuntu 20.04 LTS "Focal Fossa" - Alpha amd64 (20200123)
SourcePackage: virtualbox
UpgradeStatus: No upgrade log present (probably fresh install)