Maybe I found the source of the problem with RDP not working:
Well, in armbian-config in the file https://github.com/armbian/config/blob/master/debian-config-jobs
RDP is installed using:
if! is_package_manager_running; then
debconf-apt-progress - apt-get -y install xrdp vnc4server xorgxrdp
systemctl enable xrdp.service> / dev / null 2> & 1.
As it turns out, there is no such vnc4server package because:
root@arm-64:~# apt-get install vnc4server
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package vnc4server is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'vnc4server' has no installation candidate
Can you get around as this?