I’ve found the solution for my environment.
I need to set in node.cfg of the node:
DefaultDesktopCommand /usr/bin/startxfce4
AvailableSessionTypes unix-xsession-default,xsession-xfce
and in server.cfg of the node
ConnectPolicy autocreate=1,autoconnect=1,automigrate=1,desktop=1,dialog=1,xsessions=0,udp=1
xsession was set to 1 in my server.cfg on the node.
Thank you for your help, this topic can be marked as solved.