This is probably more than you wanted, but see:
https://forums.developer.nvidia.com/t/video-output-does-not-show-up-because-opengl-failed-to-create-x11-window-imagenet-camera-failed-to-create-opengl-display/68681/7
A shorter description is that the default server displays to a monitor only. A different server has to be installed if it is to “pretend” that the other end of a network connection is the local system…that’s the virtual desktop. Quite often someone will install a server which overwrites the original server, and if the new server does not have the correct interface to load the NVIDIA GPU driver, it will go black.
Someone else who has actually installed one of the X servers with virtual remote desktop which works from a Jetson will probably need to comment.