Hello Joseph,
Thank you for posting in the Microsoft Community! It sounds like your Surface Book 2 screen randomly goes black while in use, even though the keyboard lights stay on.
This is a fairly common issue and can be caused by a mix of power management settings, driver problems, or hardware faults. May i know what kind of troubleshooting you do?
incase no troubleshoot done yet. you can to Force restart the device, Hold the Power button for 20–30 seconds until the keyboard lights turn off.
Wait a few seconds, then press the power button again to restart.
And you can Run Surface Diagnostic Toolkit https://support.microsoft.com/en-us/surface/fix-common-problems-using-the-surface-app-and-surface-diagnostic-toolkit-f61d8d18-37a9-863d-f8d0-1982eb16f7b5
Reference link
Please feel free to reply if you need further clarification.
Warm regards,
Jay Mark