Are you connecting to a Gnome desktop? We are aware of an issue on Alma Linux when connecting to Gnome. It is not present in the latest Red Hat or Fedora versions. It’s possible to run only 1 GNOME desktop per-user. This looks to be a limitation of dbus-GNOME on Alma Linux, not present on RHEL.
A possible solution is to adopt a different desktop environment like XFCE.
You should also check the DefaultDesktopCommand in node.cfg on the server. What is written there? Journalctl output would also be useful.
We were able to run one GNOME virtual desktop by NoMachine by using any of these command in /usr/NX/node.cfg (all on a single line):
DefaultDesktopCommand "env DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus /bin/dbus-run-session gnome-session --session=gnome"
or for GNOME classic:
DefaultDesktopCommand "env GNOME_SHELL_SESSION_MODE=classic DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus gnome-session"
To try XFCE:
sudo dnf install epel-release
sudo dnf group install "Xfce"
Then set in /usr/NX/etc/node.cfg:
DefaultDesktopCommand “startxfce4