Native RDP to Windows 7 Guest not working

[Trippynet]

Hi all, I've got a strange problem with accessing a VirtualBox guest via RDP.

Host is running Ubuntu 17.04 and VirtualBox 5.
Guest is Windows 7 SP1 x64
Network is running in Bridged mode and has a static IP for both the host and guest.
Remote Desktop is enabled on the guest, I've tried it in both the Network Level Authentication mode, and the "any version" mode.

The issue is that I have another Windows 7 PC on my network, and I cannot connect to the VirtualBox Guest Windows 7 OS via RDP (using Windows native RDP, not VirtualBox's VRDP). If I try, it pauses for several seconds, then gives the generic error box "Can't connect for one of these reasons, remote access to the server is not enabled, the remote computer is turned off, etc". It does not prompt for credentials. I've tried connecting via both hostname and IP address.

Thing is, I can ping the Guest, and I can browse file shares on it fine. I can also RDP from the Guest OS to other machines on my network, I just can't seem to connect to it via RDP. I have tried disabling Windows Firewall completely on both the Guest and the PC I'm trying to connect from, still no joy.

Does anyone have any suggestions? I've searched around quite a lot without success. Did find another person on the Spiceworks forums with the same issue, but they ended up resolving it by switching to VMWare Player, which isn't really a solution IMO.

Any suggestions for getting this working would be very welcome, thanks!

[socratis]

Well, I can't help you (unfortunately), I can only verify the same behavior. On my OSX host I tested a Win7 VM and a 10.13 VM. I tried to RDP to them from both my localhost as well as another computer on the network, both in Bridged and in HostOnly modes. Nothing.

I don't claim to be a master of RDP, but I've done it before, mainly the VRDP so I know it could work. BTW, firewalls were off on everything.