I cannot reproduce your problem.
I have tested the same ISO on real hardware in live mode. I let the screen go black. I moved the mouse to get the screen back again and it came right back.
Perhaps you could try downloading the ISO again or try the MATE ISO and see if that works

I tested on an earlier version of XFCE GhostBSD. Downloading the 21.11.24 version now to see if I get the same problem. Please wait.
What graphics card are you using?

Have you tried using the live USB on real hardware and seeing if the same problem exists?

Hi. Welcome to GhostBSD! Sorry about the trouble you're having. I'm running the same version of GhostBSD as you and I have no trouble. Unfortunately I don't run Linux or use VirtualBox. I think you're correct that it's probably a problem with the screensaver. You could open the screensaver settings ...