Windows GUI Issue

Am running Qubes 4.0, not 4.1

I have successfully installed Windows 10 as a Standalong Template, following the instructions.
I then started the QWT and reached the point where you run
qvm-features win10 gui 1
qvm-prefs win10 qrexec_timeout 300

Now, when I start the windows qube, nothing appears. QUbes manager says it is running and it is consumer the normal amount of RAM / CPU but nothing is visible.

Googling says to try qvm-start-gui win10 which returns:
win10: Starting GUI
win10: Sending monitor layout
win10: Failed to send monitor layout: b’connect: No such file or directory\n’

I also tried qvm-features win10 gui 0 but nothing happens.

Can someone help? Was working fine up until this point.

Does starting the qube in debug mode helps to identify the problem closer?