VNC, CARLA and Debian 10

Hello fellow humans,
bulid a Server with Debian 10 XFCE to run CARLA Simulator. I use a RTX2060 Super with Driver 350.08. Now I try to connect with VNC to my server, but once I run glxgears it says it cannot open display. Even with the correct number of the vitual Display. It grinds my gears.